AR Sponsor
Posted: 10/13/2011 11:19:25 AM EDT
| Built an AR15 9mm carbine using considerable input gleaned from these boards. I'm hoping to get some advise to cure functioning problems encountered at the range. The rifle at issue is a RRA upper mated to a DPMS lower & parts kit, Rogers collapsible stock SPIKES ST-9X buffer with a standard CAR spring. I'm using 20 & 32rd. C-Products & BUSHMASTER magazines and have experienced the same problems with each. Ammo used is FEDERAL & REMINGTON 115gr. ball and MAGTECH 124 gr. ball; a limited number of Winchester 127 +P+ JHPs fired and functioned without issue ( once I've worked the kinks out of the gun and put a few boxes thru it, this will probably serve for ZOMBIE defense). For obvious economic reasons it need to reliably shoot ball ammo. The malfunctions experienced include several two or three shot bursts ending with the hammer down on an empty chamber or a jam with the spent case sandwiched between a live round and the chamber, some stovepipes and other jams with the empty case mouth wedged atop and behind the fresh round from the magazine. The problems happens with all 3 magazines (all are new) every 5-6 shots. I've struggled thru 4+ boxes in the forelorn hope that it would break in & iron itself out but I ain't have much fun yet. I suspect that the 8.5 oz. buffer might be a factor but bought it cuz everyone using them liked them...would a weaker spring allow the bolt to cycle longer...is an extra power spring needed or a different buffer...ejector related? I especially want to eliminate doubling. I welcome all suggestions or recommendations as my range sessions are limited and would like to get this resolved ASAP |
|
Are you using the RRA bolt? Did you have the bolt ramped? If you did not have the bolt ramped are you using the correct RRA Special 9mm hammer and NOT the standard DPMS rounded hammer?
I have a build similar to yours but I used the correct 9mm RRA hammer and the RRA 9mm buffer. Once I got the mag well adapter in the right position it runs 100% will all the magazines you have listed. Some will tell you to dump the mags and go with MetalForm. Maybe they had to do that to their rifle but mine runs fine with ProMags, CProducts, etc.I have never had a MetalForm mag in it as how much better than the 100% functioning I get now can a magazine be? 9mm carbines can sometimes make you pull your hair out. There has been a lot written on this, and other, sites about tuning them. Do some research. Start with the basics like getting the magwell adapter down low where it needs to be, making sure the ejector is positioned just right, etc. All of this can be found with some searching. Both my 9mm carbines pretty much function with whatever ammo I put in them from high powered stuff to the reduced range loads I did for my pistols. Search Is your friend. |
|
Quoted:
...a limited number of Winchester 127 +P+ JHPs fired and functioned without issue... If you are saying that the gun works 100% with the +p+ and only has issues with the lower powered ball ammo, then it is likely a buffer weight issue (too much weight). Try a ~3 oz. std. car buffer or a ~5 oz. std 9mm buffer with the lower powered ball ammo and see if it runs any better. If it does, you may just need 500-1K rounds of break in to smooth things out - even then, you may still have some issues with underpowered ammo like REM UMC. If you haven't already, you should probably get your bolt ramped and get kns pins - it's cheap insurance and the chicks really seem to dig it... 
|
|
I had very similar problems today (mine is a RRA 9mm lower ((all factory)) with a 7.5 inch RRA upper). I kept getting a failure to eject with the empty case wedgeing itself against the bolt and the live round that was mostly chambered or stovepiping.. All my magazines are new COLT magazines. I was using Reminton (UMC) 9mm ammo and i think that it was underpowered. This was only the third time that I had fired it since getting my stamp. The first time I had problems but that was due to using a very heavy buffer. I put the stock buffer back in and shot approxinmately 600 rounds of winchester white box with out any issues. Today i was shooting the remington (UMC) 9mm and had nothing but the above described issues. I got home and loaded some dummy rounds and practiced hand cycleing the action. When i cycled it hard, the rounds flew out with good force. When i kind of half assed cycling it, the rounds would get hung up like they did at the range.
My thoughts is that the ammo i was using is underpowered, but will shooting 1000 rounds of higher power ammo 'break it in" or am i doomed to only using higher power ammo in it? Is it safe to use the lighter CAR buffer to increase bolt vel;ocity which would make up for the lower power UMC ammo? |
|
Quoted:
My thoughts is that the ammo i was using is underpowered, but will shooting 1000 rounds of higher power ammo 'break it in" or am i doomed to only using higher power ammo in it? Is it safe to use the lighter CAR buffer to increase bolt vel;ocity which would make up for the lower power UMC ammo? I have over 10K through mine - non-ramped bolt, lightened hammer/trigger springs, ~5 oz. std. 9mm buffer - and it will run my 125 gr. lead reloads that are considerably weaker than REM UMC...It had problems initially with REM UMC, but I don't remember when it broke in enough to stop having issues...If you don't want to shoot it to break it in, just hand cycle the action a thousand times... 
|
Don't have the time or patience to hand cycle that thing 1000 times 
I think i'll run a few boxes of +P that I have and then a few boxes of the WWB 9mm and then test it with the UMC. When it runs, its an awesome stick. i'll just have to test more ammo with it.Thanks for the info Quoted:
Quoted:
My thoughts is that the ammo i was using is underpowered, but will shooting 1000 rounds of higher power ammo 'break it in" or am i doomed to only using higher power ammo in it? Is it safe to use the lighter CAR buffer to increase bolt vel;ocity which would make up for the lower power UMC ammo? I have over 10K through mine - non-ramped bolt, lightened hammer/trigger springs, ~5 oz. std. 9mm buffer - and it will run my 125 gr. lead reloads that are considerably weaker than REM UMC...It had problems initially with REM UMC, but I don't remember when it broke in enough to stop having issues...If you don't want to shoot it to break it in, just hand cycle the action a thousand times... |
|
If you are using C-Products mags with the RRA magblock, you will need to adjust the block about .020 lower then
flush with the top of the magwell to avoid FTF and FTE issues. What to do: 1) Ditch the C-Products mags and get Metalform. No fuss, they're expensive but work everytime. You can start with buying just one. Test it. If problem goes away........stock up. 2) Use a ramped 9mm bolt in combination with a standard AR15 hammer. Suggest the un-notched version used by DPMS. A non ramped 9mm bolt re-cocks the hammer in less than 1/2" of bolt stroke. As a result, the hammer is thrown back very fast. That method of re-cocking hurts your hammer pin and your lower receiver hammer pin holes. The ramped bolt, on the other hand, re-cocks the hammer in 1 1/4" of stroke. 3) Keep the heavy buffer and spring. It is not the problem. |
|
Hi, I wish I could add some cures here but am going through the same problems. I have an RRA upper with a Hahn mag well adapter. I have a 9mm hammer with out a notch. A DMPS I believe? Also a 9mm buffer. JP Armory lower Just a couple thoughts.
I tried an RRA mag, a C Products and a couple Pro Mags. I got about the same performance out of all of them although one Promag seemed to be more prone to problems than the other. The PRomag follower is quite different from the RRa and C prod . mags. In looking at the Hahn block, It just doesn't look like the feed ramp is low enough. Lots of brass coloration on that ramp as rounds bump up into the chamber. I have the one that installs through the top from an open action. I don't want to modify it because I may want to sell it. I just got fed up and ordered a Double Diamond dedicated 9mm lower which arrives Tuesday. http://www.shop.doublediamondsupply.com/ Their quality is supposed to be excellent. (They also are making one that works with Glock mags I believe. Not available yet) My problems include occasional stove pipes with lighter loaded ammo. I get a quite consistent problem with the last live round popping out of the mag and just laying in the chamber area sometimes backwards. The most aggravating problem is the empties that fail to eject and get wedged behind the ejector with a live round jammed up against the top of the chamber opening. Last time I shot it, I took along a needle nose pliers to extract the trapped empties. I noticed a couple things. 1. It's light load ammo sensitive. It did not like Blazer 115 but shot Rem. Magtech, Fiocci and PMC just fine. The Rem and PMC are 1150 fps rounds and the others 1230 and 1260 fps. Haven't tried the 124 grain loads yet. The gun definitely likes the stout loadings better. I had virtually no problems with the Magtech and Fiocci except the last round premature ejection. I have hand loaded up some rounds with 8.0 grains of Blue Dot and 115 bullets to get them up in the 1225-1250 range. It will be interesting to see how this slow powder works with a longer barrel to burn in. I used to use it a lot to shoot 38-55 rifle cast bullet loads and liked it a lot not that it means anything here. I also noticed the gun seems to do better when gripped tighter. I presume this is due to the blow back design. I'd say keeping the gun clean was a priority but then my least problems occurred with the gun dirty with about two hundred rounds fired. I have kept the gun well lubricated to keep it running. Tri flow is the latest I've used. I also ordered a lighter than normal spring from Brownells I will cut it to carbine length and try that some time as well. So for now, the plan is to try the Double Diamond lower and a lighter action spring if needed. I'll also go to a Metal form mag just for curiosity. I also want to check if any improvement comes from my hand loads then move to a hand loaded 124 in the 1200 fps range although I'd much rather just get the gun tuned to run on whatever is on sale this week at the gun store. By the way, I have a Stag lower with a Tactical Solutions upper that runs like a scalded ferret. No issues what so ever. |
|
My issue turned out to be low velocity ammo. To recap, I have a RRA 9mm lower (factory 9mm buffer, hammer, magazine block etc) and a 7.5 inch RRA upper. I am only using COLT marked 32 and 20 round magazines. (Both pre ban and "ban" marked). I had a C product 20 round magazine that was worthless with all types of ammo. As of today, i have just under 1000 rounds through it.
When I use Winchester White box 115 grain ammo or any +p loading I don't have any issues. When I use the Remington UMC ammo (Either FMJ or JHP) i have consistent FTE. I did some checking and determined that the Remington UMC 9mm 115 grain FMJ load has a muzzle velocity of 1135 FPS (329 ME) and the JHP has a muzzle velocity of 1155 FPS (341 ME). It seems that any load under approx 1160 FPS is what is currently causing me trouble. I also think - based on feed back from here- that after i get 1000-2000 rounds through this that the lower power ammo should start to function more reliably. Here's a list of what I have been using that has functioned flawlessly through it: Winchester White box 115 grain FMJ (1190 FPS / 362 ME) Federal 9mm JHP (Hi-shock) 115 grain (1180 FPS / 356 ME) Black Hills 9mm +p 115 grain JHP (1300 FPS / 431 ME) M882 Ball (1263 FPS / ME unknown) The Black Hills and M882 ball hauls ass out of the stick and i am going to run 500 rounds of it through the stick and then run a test magazine of the UMC to see if it'll handle the lower velocity stuff. I got the Ballistic information from: www.ballistics101.com/9mm.php or via other internet sources. Hope this helps. |
|
Quoted:
My issue turned out to be low velocity ammo. To recap, I have a RRA 9mm lower (factory 9mm buffer, hammer, magazine block etc) and a 7.5 inch RRA upper. I am only using COLT marked 32 and 20 round magazines. (Both pre ban and "ban" marked). I had a C product 20 round magazine that was worthless with all types of ammo. As of today, i have just under 1000 rounds through it. When I use Winchester White box 115 grain ammo or any +p loading I don't have any issues. When I use the Remington UMC ammo (Either FMJ or JHP) i have consistent FTE. I did some checking and determined that the Remington UMC 9mm 115 grain FMJ load has a muzzle velocity of 1135 FPS (329 ME) and the JHP has a muzzle velocity of 1155 FPS (341 ME). It seems that any load under approx 1160 FPS is what is currently causing me trouble. I also think - based on feed back from here- that after i get 1000-2000 rounds through this that the lower power ammo should start to function more reliably. Here's a list of what I have been using that has functioned flawlessly through it: Winchester White box 115 grain FMJ (1190 FPS / 362 ME) Federal 9mm JHP (Hi-shock) 115 grain (1180 FPS / 356 ME) Black Hills 9mm +p 115 grain JHP (1300 FPS / 431 ME) M882 Ball (1263 FPS / ME unknown) The Black Hills and M882 ball hauls ass out of the stick and i am going to run 500 rounds of it through the stick and then run a test magazine of the UMC to see if it'll handle the lower velocity stuff. I got the Ballistic information from: www.ballistics101.com/9mm.php or via other internet sources. Hope this helps. Interesting, I can shoot the Rem 115 FMJ through mine all day long without a single malfunction. RRA .223 lower w/magwell adapter, RRA upper... |
|
Quoted:
Quoted:
My issue turned out to be low velocity ammo. To recap, I have a RRA 9mm lower (factory 9mm buffer, hammer, magazine block etc) and a 7.5 inch RRA upper. I am only using COLT marked 32 and 20 round magazines. (Both pre ban and "ban" marked). I had a C product 20 round magazine that was worthless with all types of ammo. As of today, i have just under 1000 rounds through it. When I use Winchester White box 115 grain ammo or any +p loading I don't have any issues. When I use the Remington UMC ammo (Either FMJ or JHP) i have consistent FTE. I did some checking and determined that the Remington UMC 9mm 115 grain FMJ load has a muzzle velocity of 1135 FPS (329 ME) and the JHP has a muzzle velocity of 1155 FPS (341 ME). It seems that any load under approx 1160 FPS is what is currently causing me trouble. I also think - based on feed back from here- that after i get 1000-2000 rounds through this that the lower power ammo should start to function more reliably. Here's a list of what I have been using that has functioned flawlessly through it: Winchester White box 115 grain FMJ (1190 FPS / 362 ME) Federal 9mm JHP (Hi-shock) 115 grain (1180 FPS / 356 ME) Black Hills 9mm +p 115 grain JHP (1300 FPS / 431 ME) M882 Ball (1263 FPS / ME unknown) The Black Hills and M882 ball hauls ass out of the stick and i am going to run 500 rounds of it through the stick and then run a test magazine of the UMC to see if it'll handle the lower velocity stuff. I got the Ballistic information from: www.ballistics101.com/9mm.php or via other internet sources. Hope this helps. Interesting, I can shoot the Rem 115 FMJ through mine all day long without a single malfunction. RRA .223 lower w/magwell adapter, RRA upper... From what Kevins_garage was saying, i think that after mine get broken in a little more, it should be able to run with the lower velocity stuff. I've got tons of the higher velocity stuff so and what i'll do is shoot 2-3 hundred rounds of the high vel stuff and then try a few rounds of UMC and if it doesnt work then fire a few hundred more and so on. Did you have the bolt ramped on your 9mm? |
|
Quoted:
Quoted:
My issue turned out to be low velocity ammo. To recap, I have a RRA 9mm lower (factory 9mm buffer, hammer, magazine block etc) and a 7.5 inch RRA upper. I am only using COLT marked 32 and 20 round magazines. (Both pre ban and "ban" marked). I had a C product 20 round magazine that was worthless with all types of ammo. As of today, i have just under 1000 rounds through it. When I use Winchester White box 115 grain ammo or any +p loading I don't have any issues. When I use the Remington UMC ammo (Either FMJ or JHP) i have consistent FTE. I did some checking and determined that the Remington UMC 9mm 115 grain FMJ load has a muzzle velocity of 1135 FPS (329 ME) and the JHP has a muzzle velocity of 1155 FPS (341 ME). It seems that any load under approx 1160 FPS is what is currently causing me trouble. I also think - based on feed back from here- that after i get 1000-2000 rounds through this that the lower power ammo should start to function more reliably. Here's a list of what I have been using that has functioned flawlessly through it: Winchester White box 115 grain FMJ (1190 FPS / 362 ME) Federal 9mm JHP (Hi-shock) 115 grain (1180 FPS / 356 ME) Black Hills 9mm +p 115 grain JHP (1300 FPS / 431 ME) M882 Ball (1263 FPS / ME unknown) The Black Hills and M882 ball hauls ass out of the stick and i am going to run 500 rounds of it through the stick and then run a test magazine of the UMC to see if it'll handle the lower velocity stuff. I got the Ballistic information from: www.ballistics101.com/9mm.php or via other internet sources. Hope this helps. Interesting, I can shoot the Rem 115 FMJ through mine all day long without a single malfunction. RRA .223 lower w/magwell adapter, RRA upper... Lot of different parts out there - lot of different tolerances - sometimes they stack in your favor and other times they don't. Also explains why some folks bust up hammer pins left and righ in their 9's and 22's and others don't... |
|
Positive information on my 9mm problems.
1. I hate it when I forget something I know then get stressed out until I learn it again. New guns need breaking in. A lot of my problem went away when I accumulated about 400 rounds fired. 2. Thanks for the ejector tip. I turned the point of my Hahn block ejector close to the groove in the bolt and all my FTE with fired cases went away. 3. I still have FT Load on the last round in the mag. It pops out and lays in the chamber area and gets jamed in various positons. This is mag related. I ran four different mags today. One RRA, one C Products and Two ProMag Magazines. All ten round size. I loaded thirteen different kinds and loads of ammo into these mags five rounds at a pop and shot it all up. The best magazine was the C Products. Zero incidents of popping out the last loaded round. Second up was the One of the Pro Mags. I only got two out of thirteen loads. Third worst mag was the other Pro Mag. I only loaded that one up six times and three popped last rounds. 50% failure. Worst magazine is the most expensive. The $45 RRA magazine. (Remmeber I have an RRA upper. Should match right?) With the RRA mag, I had seven pop outs on thirteen loads. A little more than 50% of the time. Guess what mags I'll be using in the future. 4. Ammo: Now that the gun is broken in, it does well with virtually all kinds of ammo. On the lightly loaded 115 grain rounds, you can hear the action slow down. You can sense the slowness in the cycling. Other 115 loads just blew through it with a sense of authority missing in light stuff. Remington seemed the weakest although it did cycle reliably, I just had the feeling it was working just above the threshold of a FTE> 115 grain ammo: Best 115 grain ammo results was with American Eagle by Federal. Not only did it yield quarter size groups at 25 yards but exercised the gun with authority. Same sure fire for the Fiocci 115 but not quite as accurate. Other ammo that previously gave me problems worked okay. Blazer Brass, PMC. My home loads of 115 grains and eigth grains of Blue Dot worked fine with both jacked and copper plated swaged bullets. Same load with a 124 grain jacketed or copper plated bullet did well. In fact I was impressed with how well the copper plated bullets functioned. My only reservation with the slow burning Blue Dot Powder is that an occasional unburned flake came out with ejection and I could feel a mild sting on the cheek. I would have thought it would burn more completely, but apparently not. Other 124 grain loads were American Eagle again. The gun functioned perfectly but not quite as accurate as the 115 grain American Eagle. Last ammo tried was some Fiocci 147 grain heavyweights. Gun functioned well and recoil was less than the more stoutly loaded 124 and 115 bullets but these 147 grain loads were ragged. Shooting Apple size groups at 25 yards. Probably a barrel twist situation. So that is it. I'll get C Product mags and shoot the more energetic ammo and problems solved. That said, my new Double Diamond lower arrives tomorrow so I get to test again to see if the gun still likes the same magazines etc. Then once the mag well block is removed my current lower might need an Olympic Arms upper in 45 acp. Olympic arms now makes 10 round mags for that gun. |
|
2. Thanks for the ejector tip. I turned the point of my Hahn block ejector close to the groove in the bolt and all my FTE with fired cases went away.
That is the number one cause of feed and eject problems with the 9mms. UMC ammo IS underpowered. Winchester white box is loaded to NATO pressures. Blazer Brass and PMC seem to work well in my 9mm. rifle. Mine runs great with C Products and Metalform magazines. |
|
Just got in the Double DIamond lower. Looks like very nice quality. Got the usual ten day wait so I can build it later in the month.
I wanted "Safe-Fire" etching but they didn't have any in stock so I took one "Safe-Semi". They shipped immediately because it was in stock. I didn't really need the whimsical "Safe-Zombie" designation on the lower. (:^) I am now on the fence because I got the RRA/Hahn/Cproducts combo humming. But then, I never was one to not go overboard. I guess if the DD lower works out, I will free up the current lower for an Olympic 45acp upper. It's the least hassle and they now make ten round mags for those of us still in LaLa land. I like the Olympic because I can switch it to a 5.56 lower in a minute. Fun with guns. |
| Got back to the range today...still got troubles! I changed the hammer from a DPMS to RRA 9mm, replaced the 8.5 oz. Spikes buffer with a 5.9 oz. 9mm buffer, added a 9mm buffer spring from Brownells and lowered the mag well adaptor as low as possible. The first 2 C-products 20 rd. magazines function flawlessly except that all shots were 2 or 3 rd. bursts! (My carbine is semi auto with no full auto parts, modifications or provisions). Several subsequent 30 rd. mags brought mixed results...one mag loaded with 124 grain MAGTECH ammo fired flawlessly with no jams or stopages & semiauto only. The remaining four had frequent jams (FTEs) and seemingly at random fired 1, 2, 3, or 4 shots at a time. While my son gets a big charge out of this, I have little use for a weapon that goes full auto whenever the urge hits it. A reference was made to tweeking the ejector. I suspect that might be where part of the problem lies and assuming I can find out how, will be my next course of action to address the jamming issue. I've dissasembled the gun and checked all the parts (they are all from a new DPMS LPK). Before I bother our parish priest about performing an exorcism, does anyone have any suggestions. |
|
Quoted:
Got back to the range today...still got troubles! I changed the hammer from a DPMS to RRA 9mm, replaced the 8.5 oz. Spikes buffer with a 5.9 oz. 9mm buffer, added a 9mm buffer spring from Brownells and lowered the mag well adaptor as low as possible. The first 2 C-products 20 rd. magazines function flawlessly except that all shots were 2 or 3 rd. bursts! (My carbine is semi auto with no full auto parts, modifications or provisions). Several subsequent 30 rd. mags brought mixed results...one mag loaded with 124 grain MAGTECH ammo fired flawlessly with no jams or stopages & semiauto only. The remaining four had frequent jams (FTEs) and seemingly at random fired 1, 2, 3, or 4 shots at a time. While my son gets a big charge out of this, I have little use for a weapon that goes full auto whenever the urge hits it. A reference was made to tweeking the ejector. I suspect that might be where part of the problem lies and assuming I can find out how, will be my next course of action to address the jamming issue. I've dissasembled the gun and checked all the parts (they are all from a new DPMS LPK). Before I bother our parish priest about performing an exorcism, does anyone have any suggestions. If it runs fine with one ammo and not another, it is more than likely ammo related or the mags you were using were rubbing the bolt and causing it to slow down. What ammo was it bursting with? What 30 rd mags did you use with the magtech ammo that worked fine? Do you have a std. car buffer you can try with the ammo that burst fired? Can you try that ammo in the 30 rd mags and see if it still bursts? |
| All six magazines are new C-Products (the 30 rd. with orange followers) non have the two vertical dents on the sides that I've seen on some others. Ammo used was PMC, Winchester & Federa115 gr. ball & MAGTECH 124 Gr. ball. I do have .223 buffers and will try that next trip to the range. Could it be something with the trigger or disconnector?. Has anyone experianced a similar problem? |
|
Quoted:
All six magazines are new C-Products (the 30 rd. with orange followers) non have the two vertical dents on the sides that I've seen on some others. Ammo used was PMC, Winchester & Federa115 gr. ball & MAGTECH 124 Gr. ball. I do have .223 buffers and will try that next trip to the range. Could it be something with the trigger or disconnector?. Has anyone experianced a similar problem? I will wager if you simply ditch the C-Products mag for a Meltalform mag, reposition the magblock so that the top surface is flush with the magwell deck and test fire.......problem goes away. The magblock may or may not require any further adjustment. I suggested this in an earlier post. Had similar problem, ditched the C-Products and it's been 100% since. Numerous threads have been generated regarding the ills with C-Products 9mm mags over a period of years. They are half the price of a Metalform, well built, but way too fussy. Best of luck. |
|
I see these posts where MetalForm mags are the magic Snake Oil that cures all evils in 9mm ARs. If only that were so! I have two 9mm AR's that I have been shooting the past few years. I run CProducts, ProMags, and the RRA mod'ed mags. They all run fine...once the mag well was properly adjusted.
With Mag Well adapters a few thousands of an inch is the difference between a nightmare and a great time at the range. Been there, done that. Once I made sure everything was properly adjusted my babies ran great on whatever mag I gave them. True, ProMag is my personal last choice due to their cheap plastic construction, but mine do run OK in both my AR's. I do avoided stuffing them with all 32 rounds however, they are a bit "fat" when stuffed. I have never run a MetalForm mag in my rifles. They may be the greatest things sine sliced bread but since my CProducts and ProMags are 100% reliable when the mag well is adjusted properly I see no reason to spend a lot of money on expensive magazines when the rifle (magwell adjustment) is the real problem. I think that some of these rifles that were "cured" by Metal Form mags may have been OK if the other parts had been adjusted properly. JMHO. |
|
Quoted:
I see these posts where MetalForm mags are the magic Snake Oil that cures all evils in 9mm ARs. If only that were so! I have two 9mm AR's that I have been shooting the past few years. I run CProducts, ProMags, and the RRA mod'ed mags. They all run fine...once the mag well was properly adjusted. With Mag Well adapters a few thousands of an inch is the difference between a nightmare and a great time at the range. Been there, done that. Once I made sure everything was properly adjusted my babies ran great on whatever mag I gave them. True, ProMag is my personal last choice due to their cheap plastic construction, but mine do run OK in both my AR's. I do avoided stuffing them with all 32 rounds however, they are a bit "fat" when stuffed. I have never run a MetalForm mag in my rifles. They may be the greatest things sine sliced bread but since my CProducts and ProMags are 100% reliable when the mag well is adjusted properly I see no reason to spend a lot of money on expensive magazines when the rifle (magwell adjustment) is the real problem. I think that some of these rifles that were "cured" by Metal Form mags may have been OK if the other parts had been adjusted properly. JMHO. Nice to know everything worked as planned for you. Metalform mags are not magic snake oil, they just plain work. Check the web for yourself. Stories are numerous and span pages across a variety of boards similar to ARFCOM. From FTF, FTE, faulty bolt hold open, faulty drop free function, etc, etc, etc. C-Products 9mm mags are troublesome. Ironically, users of the cheap plastic Promags have reported far less woes. I've used them briefly without issue. Metalform was the original Colt supplier, got dropped and replaced by low bidder C-Products some years back. Guess what? C-Products got dropped and now Colt is back to Metalform as primary supplier. That should speak volumes alone. I also tried to find a single instance where someone complained about the function of a Metalform mag that was fixed by C-Products....NADA!!! For the record, C-Products advised customers using an RRA magblock to lower it by .020" from flush with the magwell deck for proper function. Doing so however, also puts in question the reliable function of any other mag you plan to use. Finally, C-Products LLC is no longer. I believe the company producing the magazines is named A.S.C. LLC. |
|
I also tried to find a single instance where someone complained about the function of a Metalform mag that was fixed by C-Products....NADA!!! There you go, adding words to what was said. I went back and re-read this thread and nowhere did it mention that C-Product mags would "fix" a problem gun, nowhere. What was said is that making small adjustments to other parts will often "fix" the problem. MetalForm magazine may tolerate some things being out of adjustment and in that regard perhaps you are right, for people who do not know how to tune a rifle perhaps they do need to go out and spend the money on more expensive magazines. Not everyone understands how to get a firearm to work properly. There is a lot to know and learn and sometimes after living with these things for years one can forget that others may not have the time, patience, or understanding to put into optimizing a firearm. Its been a hobby of mine for well over forty years and perhaps during that time I have learned to look a bit deeper and fiddle with things a bit more. I do recall when I put my first 9mm rifle together it was not 100% on the first few outings. Doing a little research and tinkering I got the little bugger to run like a champ. It was all simple stuff, minor adjustments, most of which have been covered here. To me this is the fun part of the shooting hobby. I should realize that others just want to pick up or build a new rifle and have it purr out of the box. I don't argue with that at all. Guess to some of us the fun is learning the piece inside and out and then mastering how to make it function perfectly. For us over coming a few issues is the half the fun of the sport. To those who don't care to go through this, or don't have the time to fiddle and play with the rifle, go buy the Metal Form mags and go shoot. They may, or maynot, solve your problems. If they do fix it, your a happy camper. Oh, and if you have any old junk C-Producet 9mm mags you want to trash, let me know I will pay for the shipping and take them off your hands. |
| I've used 6 different 30 rd (C-products & Bushmaster) & 2 C-products 20 rd. mags all of which were new. I've set the adaptor flush with and lower than the rim of the magwell and had the same type of malfunction with all of them. It appears that the spent shell is not ejected and is driven in front of the bolt and jams in between the fresh round and top of the upper receiver / rear of the barrel. I've looked at the ejector and it appears be riding in the right groove in the bolt but am not sure of what I should be looking for. I will try a Metalform mag to see if it makes a difference. I intend to use the lower from my son's Armalite after installing the 9mm hammer next trip to the range...that should tell me something. I noticed that the trigger and disconnectors are different between the Armalite & DPMS...I had assumed all parts would be of the same design. The DPMS dealer at the local gunshow yesterday seemed to think that the trigger might have been installed wrong but couldn't suggest how this could be done. The whole assembly seemed pretty straight forward...also if full auto capability could be achieved simply by installing a semi auto part differently, it would 1. be all over the internet 2. give the ATF a stroke & 3. cause the stock of ammunition companies to rise at leas 30%. I much appreciate all input received from my initial post and continue to welcome any help & suggestion toward getting these issues resolved. |
|
Quoted:
I've used 6 different 30 rd (C-products & Bushmaster) & 2 C-products 20 rd. mags all of which were new. I've set the adaptor flush with and lower than the rim of the magwell and had the same type of malfunction with all of them. It appears that the spent shell is not ejected and is driven in front of the bolt and jams in between the fresh round and top of the upper receiver / rear of the barrel. I've looked at the ejector and it appears be riding in the right groove in the bolt but am not sure of what I should be looking for. I will try a Metalform mag to see if it makes a difference. I intend to use the lower from my son's Armalite after installing the 9mm hammer next trip to the range...that should tell me something. I noticed that the trigger and disconnectors are different between the Armalite & DPMS...I had assumed all parts would be of the same design. The DPMS dealer at the local gunshow yesterday seemed to think that the trigger might have been installed wrong but couldn't suggest how this could be done. The whole assembly seemed pretty straight forward...also if full auto capability could be achieved simply by installing a semi auto part differently, it would 1. be all over the internet 2. give the ATF a stroke & 3. cause the stock of ammunition companies to rise at leas 30%. I much appreciate all input received from my initial post and continue to welcome any help & suggestion toward getting these issues resolved. You set the adapter flush with the lower...I did this on my first build and it had the same exact problems that you are describing. I finally moved the adapter down a bit lower after reading here what others had tried. I really moved that sucker down, as far as I could, and it was below being flush if I recall. I then noticed a bit of wear on my bolt hold back. So, I took a magazine and just lightly ran a file on the edge of the feed lips thinking it might be riding high on this lower and dragging on the bottom of the bolt. I will never know if the file on the feed lips or the adjustment of the adapter was the fix. I do know when I did both the rifle started running great. So, go as low with the adapter as your magazine latch will allow you. Give it a try. Check the top of your mag and the bottom of your bolt to see if anything is dragging. And, there is that hammer thing. It also could be dragging. And lastly, the ammo....I am assuming you have tried different ammo. Its so frustrating when a new firearm doesn't work. As has been pointed out, some fix themselves after a few hundred rounds. Others need a bit more help. Best of luck with this project. When you get it running right you will really enjoy it and hopefully put the bad memories of the problems behind you. |
|
Just to recap what can be done to troubleshoot:
Uncommanded multiple or "burst shots" is the fire control group and can be caused by the following: Disconnector spring is upside down. Fat end goes down in the hole. If upside down, spring can hang up on the rim of the hole preventing full travel of disconnector. If a visual check confirms proper install, then the disconnector is out of spec. It can also be hammer and/or trigger. Replace ONLY ONE piece at a time and test fire to see if problem is resolved starting with disconnector then the hammer and trigger. The failure to fire can be caused by one or multiple problems but troubleshoot in this order: Start with magblock flush with magwell deck. Take note of the clearance between where the bolt catch overlaps the magwell adapter. If failures continue lower adapter incrementally and test. C-Product suggests their mags require lowering the magblock from .015-.020" to function properly. To determine the lowest point, push in mag release while pushing down the magblock till they meet then back off. Confirm the ejector is riding up in the bolt groove, is parallel and not rubbing on the bolt. You are looking for it to be high and tight to the center of the bolt. The ejector contact surface hitting the spent case is small, so you want to maximize it for reliable ejection. Improving performance and reliability: Save your lower receiver and hammer pin by bolt ramping. A non ramped 9mm bolt re-cocks the hammer with under 1/2" of bolt stroke. As a result, the hammer is thrown back very fast. That method of re-cocking hurts your hammer pin and your lower receiver hammer pin holes. The ramped bolt, on the other hand, re cocks the hammer in 1 1/4" of stroke. CMMG, Spikes or RRA bolt from ADCO is already ramped. You can also have a non-ramped bolt machined for $70. Use with un-notched hammer such as those made be DPMS for a smooth action. Metalform magazines are widely accepted as the most reliable and are COLT OEM for their 9mm. Buy once cry once. Use a long buffer or a 9mm buffer with a machined buffer plug as found at Spikes Tactical. The 9mm does not require as much bolt travel to cycle. Doing so will eliminate bolt catch breakage that is common with this setup. |
|
Reply Quote Disconnector spring was correctly installed. All parts were from a new DPSM LPK but the surface of the trigger upon which the disconnector rides is machined white metal (no parkerizing). It seemed unusual that it is not completely coated...is this normal? The only failure to fire issues occur when the hammer is down occasionally after a full auto burst. The majority of jams are FTEs and hopefully you've put your finger on it. In examining the parts, the ejector has wear marks on the top edge that correspond to marks on the outer side of the groove in the bolt. Can the ejector be bent inward slightly ot fix this? The magblock was tried flush with the magwell and as low as it will go (about 1/16") with similar result. I will adjust that to .020. Report |
|
Yes, the unparked part of the trigger is normal.
You can bend the ejector to get it where you need it. Go slow, be gentle, but it shouldn't be a problem. When I adjusted mine, I gripped the loewr part of it with a pliers, and then used another one on the upper part I was bending. This keeps the stress off where it is pinned into the mag blocks. If you cycle the gun by hand, even as quickly as you can, does the hammer ever NOT get caught by the disconnector? I'd bet you are getting short strokes due to the ejector binding. The bolt is still moving enough to strip the next round, just not enough to reset the hammer far enough to get disconnected. |
|
Quoted:
Yes, the unparked part of the trigger is normal. You can bend the ejector to get it where you need it. Go slow, be gentle, but it shouldn't be a problem. When I adjusted mine, I gripped the loewr part of it with a pliers, and then used another one on the upper part I was bending. This keeps the stress off where it is pinned into the mag blocks. If you cycle the gun by hand, even as quickly as you can, does the hammer ever NOT get caught by the disconnector? I'd bet you are getting short strokes due to the ejector binding. The bolt is still moving enough to strip the next round, just not enough to reset the hammer far enough to get disconnected. Very probable your assessment is correct. The evidence is certainly there to suggest it. |
|
Range Update:
I shot approximately 440 rounds of the M882 ball, WWB and Black hills +p loads yesterday. Zero isssues through 15 different COLT / Metalform magazines. I then put 10 rounds of Remington UMC 115 grain ball into a magazine and it would not eject the spent casing and next round would get stuck. My choiches are to either stick to the higher velocity stuff or maybe reduce the buffer weight (Currently using the standard 9mm buffer). Im going to fire another 500 rounds of the HV stuff and then try the UMC again. Im certain that over time it will start to function with the lower velocity rounds. Quoted:
Quoted:
Quoted:
My issue turned out to be low velocity ammo. To recap, I have a RRA 9mm lower (factory 9mm buffer, hammer, magazine block etc) and a 7.5 inch RRA upper. I am only using COLT marked 32 and 20 round magazines. (Both pre ban and "ban" marked). I had a C product 20 round magazine that was worthless with all types of ammo. As of today, i have just under 1000 rounds through it. When I use Winchester White box 115 grain ammo or any +p loading I don't have any issues. When I use the Remington UMC ammo (Either FMJ or JHP) i have consistent FTE. I did some checking and determined that the Remington UMC 9mm 115 grain FMJ load has a muzzle velocity of 1135 FPS (329 ME) and the JHP has a muzzle velocity of 1155 FPS (341 ME). It seems that any load under approx 1160 FPS is what is currently causing me trouble. I also think - based on feed back from here- that after i get 1000-2000 rounds through this that the lower power ammo should start to function more reliably. Here's a list of what I have been using that has functioned flawlessly through it: Winchester White box 115 grain FMJ (1190 FPS / 362 ME) Federal 9mm JHP (Hi-shock) 115 grain (1180 FPS / 356 ME) Black Hills 9mm +p 115 grain JHP (1300 FPS / 431 ME) M882 Ball (1263 FPS / ME unknown) The Black Hills and M882 ball hauls ass out of the stick and i am going to run 500 rounds of it through the stick and then run a test magazine of the UMC to see if it'll handle the lower velocity stuff. I got the Ballistic information from: www.ballistics101.com/9mm.php or via other internet sources. Hope this helps. Interesting, I can shoot the Rem 115 FMJ through mine all day long without a single malfunction. RRA .223 lower w/magwell adapter, RRA upper... From what Kevins_garage was saying, i think that after mine get broken in a little more, it should be able to run with the lower velocity stuff. I've got tons of the higher velocity stuff so and what i'll do is shoot 2-3 hundred rounds of the high vel stuff and then try a few rounds of UMC and if it doesnt work then fire a few hundred more and so on. Did you have the bolt ramped on your 9mm? |
|
This thread is interesting.... I have been having similar problems (failure to eject) with my 5.5" build. I have tried several types of ammo, from fiocchi, WWB, and Winchester super X, and a couple different mags (products, metal form, promag).
I get 2-3 FTE's per mag on average. My magwell adapter is the spikes adjustable and I honestly do not know what to adjust with it. It is flush with the lower, but aside from that it's in factory config. |
| Well I bent the ejector to ride "high & inside" and set the adaptor at .020". Ordered the Metalform mag & Spikes buffer 'plug' but probably won't get them in time for the range Friday. Not sure if the doubling problem will be cured but am hoping the FTE / jams will go away. Will try my son's Armalite lower with my RRA upper to see if the doubling disappears. No the disconnector never fails to engage the hammer when cycling by hand. In perusing some other posts its evident that some responders have an unlimited supply of ammunition to burn. Unfortunately I am not so blessed and simply cannot expent a thousand rounds to break in a weapon based on a military design which has always performed well for me. In the late 60s I used extensively a few M16A1 rifles while in the employ of Uncle Sam. A few years later, I bought a Colt Sporter which probably went thru several cases in the 4-5 yrs. I had it. I bought my son his M4 and own a SIG 556. I could count on one hand (and still pick my nose) the number of times these weapons malfunctioned. (This includes one memorable afternoon when using eleven shooters we dumped 3000 rds. of tracer ammo thru one rifle on continuous full auto fire, stopping only to change magazines! That particular gun was of course trashed, with melted plastic handguards and a .35 caliber barrel sans rifling when it finally cooled.) My point is that I am somewhat disappointed in the reliability of this particular rendition of the AR platform. I can't help but suspect that as this is my first "build" I've missed something that is causing these problems. Aside from use as an indoor range toy during the bad weather had I hoped to use carbine this to defend my home against the winter Zombie hoards but until it's running well, will stick with my M1. |
|
Quoted:
Well I bent the ejector to ride "high & inside" and set the adaptor at .020". Ordered the Metalform mag & Spikes buffer 'plug' but probably won't get them in time for the range Friday. Not sure if the doubling problem will be cured but am hoping the FTE / jams will go away. Will try my son's Armalite lower with my RRA upper to see if the doubling disappears. No the disconnector never fails to engage the hammer when cycling by hand. In perusing some other posts its evident that some responders have an unlimited supply of ammunition to burn. Unfortunately I am not so blessed and simply cannot expent a thousand rounds to break in a weapon based on a military design which has always performed well for me. In the late 60s I used extensively a few M16A1 rifles while in the employ of Uncle Sam. A few years later, I bought a Colt Sporter which probably went thru several cases in the 4-5 yrs. I had it. I bought my son his M4 and own a SIG 556. I could count on one hand (and still pick my nose) the number of times these weapons malfunctioned. (This includes one memorable afternoon when using eleven shooters we dumped 3000 rds. of tracer ammo thru one rifle on continuous full auto fire, stopping only to change magazines! That particular gun was of course trashed, with melted plastic handguards and a .35 caliber barrel sans rifling when it finally cooled.) My point is that I am somewhat disappointed in the reliability of this particular rendition of the AR platform. I can't help but suspect that as this is my first "build" I've missed something that is causing these problems. Aside from use as an indoor range toy during the bad weather had I hoped to use carbine this to defend my home against the winter Zombie hoards but until it's running well, will stick with my M1. You have certainly had more problems then most. Of all the ones I worked on, 99% of the time it was the magblock adjustment or magazine. Usually resolved within 30 minutes at the first range session, then 100% reliable. You'll get it ironed out. This forum is filled with folks who jumped through similar hoops and will help you where they can. On the bright side, look at how much you know about 9mm AR's now.
|
| Finally managed to put some rounds thru the AR today, tho time & weather forced me to go to an indoor range. Disassembling your firearms is frowned on there so tweeking was not possible. Fired about 250 rds. (mostly WW White box ball with some Wolf and a magazine of Ranger 127 gn. +p+ JHP). I'm pleased to report that the jamming issues largely disappeared except for the steel case Wolf (4 jams in 25 rds.) I had one incident of doubling & one triple. I used 2-20 & 3-30 rd. C-Products mags with the adaptor positioned below the edge of the magwell. I replaced the disconnector, the new one is significantly longer in the 'hook' area and bent the ejector to ride tighter inside the bolt groove. I'm generally happy with the carbine's performance; while not yet 100%, I can see light at the end of the tunnel. The "Metalform" mag I bought turned out to be a converted 40 rd.UZI mag that is too narrow to securely lock into the mag well. As I live in a State that prohibits mag capacities exceeding 30, I can't use it anyway. ( I blocked my C-Product 32 rd. mags using a trimmed roofing nail fastened to the inner floorplate with JB Weld). My sons had a blast nailing Zombie targets moving toward them between the 25 & 10 yards lines. Hopefully with a little more tinkering I'll iron out the remaining bugs and assign it closet space as a home defense gun. Many thanks to all who imparted their thoughts, ideas and solutions to this thread. |
|
Kinda interested in why it was doubling and problem was fixed with the addition of buffer spacer. I have same issue and cannot figure out why. I used CMMG 9mm (solid)buffer, Colt 9mm 2 piece buffer and Spikes ST-9X heavy buffer. Problem was better with Colt buffer and "quarters". Not happy about having to rig my gun to work properly. In my mind it should not do this at all. If someone can shed some light and explain this to me I'm all ears.
Thanks |
AR Sponsor