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Posted: 12/31/2016 1:03:32 PM EDT
For the third weekend in a row my 5.56 OBR is having feed issues. It has less than 200 rounds down the barrel, I lubed it when it was new, Slip EW Lube and agin last weekend. When I lubed it last weekend, complete bolt/carrier disassembly.
About 30 rounds today, same happened again. The first two times it did this I was using 10 round Magpuls, thinking it was a weak 10 round spring I went with 20 round Magpul today. A new mag, right out of the plastic bag last night. The spent case is ejected, but the follow up round is not feeding, as to clear it I have to pull the charging handle back, lock the BC, release the mag and the round is falling out. Today I was sighting in and the only thing I can think of is I had the mag resting on my weak side hand. The port selector is to the left as I am shooting unsuppresed. I was shooting 77 FGMM at first, but this did happened until I switched to 55 grain PMC. Not sure if this is coincidence or not, Any suggestions? |
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If I'm understanding your post the OBR ran fine until you switched to the 55 grain PMC. The OBR has really tight tolerances. Your gun may or may not have come with the extra low power white buffer spring. If not call Larue and they may be nice enough to send you the low power white spring to run with the light weight ammo. If you are running the red buffer spring in the gun stick wth quality 5.56 55 grain ammo or heavier bullet weights. After a few hundred rounds running your pmc 55 grain ammo with the white spring you can switch back to the red spring and your OBR should run just fine with the PMC. Don't get frustrated just a rifle break in thing. Also keep your bolt and bolt carrier wet with oil. Hope this helps.
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Make sure the port on the bolt carrier is clean and free from debris. Don't use a Qtip to clean this. (A friend did this on his gun and it took a trip back to Texas for them to find this). Lube the hell out of the bolt in the carrier and then the bolt lugs. Spray CLP down the buffer tube to lube the spring. Then retest.
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Quoted:
If I'm understanding your post the OBR ran fine until you switched to the 55 grain PMC. The OBR has really tight tolerances. Your gun may or may not have come with the extra low power white buffer spring. If not call Larue and they may be nice enough to send you the low power white spring to run with the light weight ammo. If you are running the red buffer spring in the gun stick wth quality 5.56 55 grain ammo or heavier bullet weights. After a few hundred rounds running your pmc 55 grain ammo with the white spring you can switch back to the red spring and your OBR should run just fine with the PMC. Don't get frustrated just a rifle break in thing. Also keep your bolt and bolt carrier wet with oil. Hope this helps. View Quote I just checked the rifle, it has the white spring installed from the factory. I have a spare red spring that Larue shipped to me with the rifle. I also checked the ammo I was shooting, the 55 grain, it is Remington yellow/green box. I pulled the rifle down and the BC was extremely dirty just from the shooting today. I have always had good success with the Remington, PMC, WW white box, my LMTs eat it up. Please do not read anything into this, but FTFs and FTEs are new to me, never had the issue. My collection is LMTs and the one LaRue. I will say this, the BC fit to the upper is very tight, you can tell the tolerance is close, as compared to my LMTs. I do not have the paper work in front of me, but I recall the PSSwitch needs to be to the left for non-suppressed. Thanks, 77 |
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Yes the PST needs to be to the left when looking down the gun toward the target for unsuppressed. Clean and lube the hell out of it. Are you getting complete bolt lock back when firing a single round from the magazine.
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Yes the PST needs to be to the left when looking down the gun toward the target for unsuppressed. Clean and lube the hell out of it. Are you getting complete bolt lock back when firing a single round from the magazine. View Quote Good question, I will check that next weekend... I am going to get some 69 grain Federal and give that a try....I just hope I don't have a fenecky eater here. like I said I only use top name ammo, never metal cased, Brown Bear, Wolff, etc... 77 |
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You don't Larue, do you? View Quote I do. I own a 5.56 16" tOBR. And? The guy who wrote that tolerance thing had a couple of things wrong. The white spring isn't a low power one, its a standard power and is Sprinco's equal to the standard Colt carbine. The red is an extra power spring, and Sprinco meant it to be used on overgassed rifles, Larue recommends it when running 5.56 pressure ammo. Tolerances...it was hard to tolerate that post. OP...are you using the factory carbine buffer? |
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Quoted:
I do. I own a 5.56 16" tOBR. And? The guy who wrote that tolerance thing had a couple of things wrong. The white spring isn't a low power one, its a standard power and is Sprinco's equal to the standard Colt carbine. The red is an extra power spring, and Sprinco meant it to be used on overgassed rifles, Larue recommends it when running 5.56 pressure ammo. Tolerances...it was hard to tolerate that post. OP...are you using the factory carbine buffer? View Quote Yes everything is as the rifle was shipped. It it 2 years old. I fired off 40 rounds December 2014 when it came in, cleaned the barrel and lubed, put it away. Just got an optic for it last month and this is where I am at..so rethinking I may have less than 150 rounds total thru the rifle. 77 |
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Some reading for you. The OP was having similar problems with his rifle...
Click me... Click me too... Generally, most malfunctions in semi-automatic firearms are magazine related. The next largest percentage is ammo related. |
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Quoted:
I do. I own a 5.56 16" tOBR. And? The guy who wrote that tolerance thing had a couple of things wrong. The white spring isn't a low power one, its a standard power and is Sprinco's equal to the standard Colt carbine. The red is an extra power spring, and Sprinco meant it to be used on overgassed rifles, Larue recommends it when running 5.56 pressure ammo. Tolerances...it was hard to tolerate that post. OP...are you using the factory carbine buffer? View Quote View All Quotes View All Quotes Quoted:
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You don't Larue, do you? I do. I own a 5.56 16" tOBR. And? The guy who wrote that tolerance thing had a couple of things wrong. The white spring isn't a low power one, its a standard power and is Sprinco's equal to the standard Colt carbine. The red is an extra power spring, and Sprinco meant it to be used on overgassed rifles, Larue recommends it when running 5.56 pressure ammo. Tolerances...it was hard to tolerate that post. OP...are you using the factory carbine buffer? ""WHITE Spring" STANDARD Power Buffer Spring. Equivalent spring load to a “fresh” Mil-Spec M4 Carbine Spring. This spring will perform reliably in any properly configured and maintained 5.56 Carbine, if you wish to maintain the performance of a “fresh” Mil-Spec load spring without concern for replacement. This is the best choice for shooters and purists that wish to maintain the performance of most factory supplied NEW Mil-Spec springs, but do not wish to be concerned with frequent replacement of same or do not have the time or inclination to seek enhanced performance options. The "WHITE" spring is recommended for 10.0"-11.0" SBR's with H2 Buffers, 1st Gen M&P's, older RRA's with under 18"+ BBL's, early generation Colt 6920 LE's, 5.56 & 6.8 SPC 7.5"-8.5" BBL Piston Guns with H2 Buffers, with few exceptions, most .300 AAC Platforms, longer carbine barrels using intermediate or rifle length gas, and when training with SRTA and other low power and light charged “budget” rounds. Color Coded WHITE. [EXCEPTIONS: With SBR's which are seriously overgassed firing suppressed, (e.g. 10.3" HK 416's), a RED or ORANGE along with a hydraulic buffer is often used with great success.] “BLUE Spring” ENHANCED Power Buffer Spring, Offers improved performance with most non-suppressed 12.5"-14.5" SBR's, 16" DI Mid-Length BBLS, and all mid-length uppers with adjustable gas blocks. Best performance is usually achieved using buffers ranging from ST-2T, H2, DPMS Extra Heavy Buffer. Will run in 18"+ Length BBL RRA'S with ST-T2 Buffers. Color Coded BLUE. “RED Spring” EXTRA Power Buffer Spring, Best option for 16"+ 5.56 barrels with carbine length gas system platforms with standard front sight towers and H buffers, 16" + BBL gas piston guns, *some* suppressed shorties,and later generation Colt LE6920's, 9mm, 6.8 SPC, 6.5 Grendel, .458 SOCOM, 450 Bushmaster, .500 Beowulf, and assorted "Thumpers" using standard 7" depth M4 extension tubes. AR-10 Carbines (E.G. Armalite, Noveske, LMT) using deeper extension tubes and standard length carbine buffers to accommodate the longer .308 BCG also use the "RED" Spring. Please call us to discuss successful historical "recipes" for implementation of the RED spring in .308, 6.8 SPC, etc. RIFLE length extension tube platforms. Color Coded RED. NOTE: NOT for use in .308 Carbines using standard 7" M4 extension tubes and short, stubby buffers. (Use our "ORANGE Spring" below for that specific platform approach application.) NOTE: If you have a seriously overgassed .308 Carbine which has the deeper AR-10 platform receiver extension tube running an H3 buffer firing 175 Gr. Projectiles and / or suppressed, many shooters have experienced success using the "ORANGE" spring, as it is still heavier than a "RED" spring in that application." So under the White spring definition you fail to read the low power? The five page and one page links you provide doesn't summarize the short helpful response I tried to provide the OP? See the exceptions under the White spring definition? Where does the OBR MID-Length gas system fit for springs and buffer weights? OP good luck with getting it running. My OBR light needed to be broken in with quality 5.56 ammo before it started running the less expensive.223 stuff due to its tight tolerances. As mentioned mine came with red spring installed I switched to the white spring for the "lowpower" ammo aka standard spring. Once it was broken in it runs everything just fine with the Red spring now. Happy Shooting and Happy New Year All! |
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Snipert,
Thanks for the info....Like I mentioned I am going to try a different ammo. I have been buying Remington/UMC, PMC and Win White box for years, all 55 grain. I was shooting the FGMM 77 grain to sight in, as that is the ammo the rifle was tested with at the LT shop. I took the rifle down again tonight during halftime of the CLEM-OS game and cleaned the bold carrier real good, lubed with Slip 2000 EWL and EWG. Cleaned the chamber and barrel, all with Slip products. The BC fits in the receiver like a glove, tighter than my LMT MRPs. Like I said, the white spring was in the rifle as it shipped, the red spring was in the box in a plastic tube. The next time I go to the range, I will run some of the ammo that was jamming with a NHMTG magazine, see if there is an issue. Thinking back today, I ran about 50 rounds of 55 grain after the 10 rounds of FGMM 77 grain. I was down loading the mags to 12-14 rounds and the first FTE was after 25 to 30 rounds of the 55 grain. The second was 10 rounds later. I am not going to overthink the issue, will try the things I mentioned. Thanks and Happy New Year to everyone. Me and the Ms are by ourselves tonight, my son and his GF are out and my LSU Tigers beat Louisville real good tonight...so all is well. 77 |
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Snipert, Thanks for the info....Like I mentioned I am going to try a different ammo. I have been buying Remington/UMC, PMC and Win White box for years, all 55 grain. I was shooting the FGMM 77 grain to sight in, as that is the ammo the rifle was tested with at the LT shop. I took the rifle down again tonight during halftime of the CLEM-OS game and cleaned the bold carrier real good, lubed with Slip 2000 EWL and EWG. Cleaned the chamber and barrel, all with Slip products. The BC fits in the receiver like a glove, tighter than my LMT MRPs. Like I said, the white spring was in the rifle as it shipped, the red spring was in the box in a plastic tube. The next time I go to the range, I will run some of the ammo that was jamming with a NHMTG magazine, see if there is an issue. Thinking back today, I ran about 50 rounds of 55 grain after the 10 rounds of FGMM 77 grain. I was down loading the mags to 12-14 rounds and the first FTE was after 25 to 30 rounds of the 55 grain. The second was 10 rounds later. I am not going to overthink the issue, will try the things I mentioned. Thanks and Happy New Year to everyone. Me and the Ms are by ourselves tonight, my son and his GF are out and my LSU Tigers beat Louisville real good tonight...so all is well. 77 View Quote Happy New Year! Same luck at home for me tonight. Your on the right track. Just don't want you to get frustrated. I absolutely Love my OBR's. Other rifles have come and go never the OBR's. Try the red spring with the 77's and 69 grain stuff. As others have mentioned as well as I, lube the shit out of it. They work better wet... I was fortunate enough to win a 20" Stealth barrel during the give away. The 69 grain Federal are 1moa. Can't wait to run 77's in it. |
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"WHITE Spring" STANDARD Power Buffer Spring. Equivalent spring load to a “fresh” Mil-Spec M4 Carbine Spring. This spring will perform reliably in any properly configured and maintained 5.56 Carbine, if you wish to maintain the performance of a “fresh” Mil-Spec load spring without concern for replacement. This is the best choice for shooters and purists that wish to maintain the performance of most factory supplied NEW Mil-Spec springs, but do not wish to be concerned with frequent replacement of same or do not have the time or inclination to seek enhanced performance options. The "WHITE" spring is recommended for 10.0"-11.0" SBR's with H2 Buffers, 1st Gen M&P's, older RRA's with under 18"+ BBL's, early generation Colt 6920 LE's, 5.56 & 6.8 SPC 7.5"-8.5" BBL Piston Guns with H2 Buffers, with few exceptions, most .300 AAC Platforms, longer carbine barrels using intermediate or rifle length gas, and when training with SRTA and other low power and light charged “budget” rounds. Color Coded WHITE. [EXCEPTIONS: With SBR's which are seriously overgassed firing suppressed, (e.g. 10.3" HK 416's), a RED or ORANGE along with a hydraulic buffer is often used with great success.] “BLUE Spring” ENHANCED Power Buffer Spring, Offers improved performance with most non-suppressed 12.5"-14.5" SBR's, 16" DI Mid-Length BBLS, and all mid-length uppers with adjustable gas blocks. Best performance is usually achieved using buffers ranging from ST-2T, H2, DPMS Extra Heavy Buffer. Will run in 18"+ Length BBL RRA'S with ST-T2 Buffers. Color Coded BLUE. “RED Spring” EXTRA Power Buffer Spring, Best option for 16"+ 5.56 barrels with carbine length gas system platforms with standard front sight towers and H buffers, 16" + BBL gas piston guns, *some* suppressed shorties,and later generation Colt LE6920's, 9mm, 6.8 SPC, 6.5 Grendel, .458 SOCOM, 450 Bushmaster, .500 Beowulf, and assorted "Thumpers" using standard 7" depth M4 extension tubes. AR-10 Carbines (E.G. Armalite, Noveske, LMT) using deeper extension tubes and standard length carbine buffers to accommodate the longer .308 BCG also use the "RED" Spring. Please call us to discuss successful historical "recipes" for implementation of the RED spring in .308, 6.8 SPC, etc. RIFLE length extension tube platforms. Color Coded RED. NOTE: NOT for use in .308 Carbines using standard 7" M4 extension tubes and short, stubby buffers. (Use our "ORANGE Spring" below for that specific platform approach application.) NOTE: If you have a seriously overgassed .308 Carbine which has the deeper AR-10 platform receiver extension tube running an H3 buffer firing 175 Gr. Projectiles and / or suppressed, many shooters have experienced success using the "ORANGE" spring, as it is still heavier than a "RED" spring in that application. So under the White spring definition you fail to read the low power? The five page and one page links you provide doesn't summarize the short helpful response I tried to provide the OP? See the exceptions under the White spring definition? Where does the OBR MID-Length gas system fit for springs and buffer weights? OP good luck with getting it running. My OBR light needed to be broken in with quality 5.56 ammo before it started running the less expensive.223 stuff due to its tight tolerances. As mentioned mine came with red spring installed I switched to the white spring for the "lowpower" ammo aka standard spring. Once it was broken in it runs everything just fine with the Red spring now. Happy Shooting and Happy New Year All! View Quote You wrote that it was a "low power" spring in the first post you made in this thread...twice no less...jeez dude. |
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You wrote that it was a "low power" spring in the first post you made in this thread...twice no less...jeez dude. View Quote Yes exactly! I also referred to it as the White spring three times. Read the whole White Spring description. Most of us would consider PMC 55 grain .223 ammo "Low Power"/ Budget ammo. Happy New Year! |
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Happy New Year!!
I have a tOBR 16" 5.56 and i shoot the Geissele braided buffer spring and it works great for 55-77 in my humble opinion just throwing out some other options but I love the explanations on here I walked away with a better understanding of a few things. Thanks fellas |
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FYI: PMC Bronze is low pressure .223, PMC X-TAC is high pressure 556.... I don't have a LaRue in 5.56 but I have a couple of other brands. The Colt HBAR shoots anything with no issues and is very accurate (when scoped). The CMMG doesn't like PMC bronze in 55gr but shoots it fine in 62gr. It was extremely finiky as a gas piston gun, much less so as a DGI weapon.
I may have to rethink this though, haven't shot the CMMG since the conversion to A2 configuration with a standard DPMS A2 buffer and JP tuned rifle spring. Either way, I don't plan on buying anymore PMC .223 Bronze. The bronze does shoot well as plinking ammo in the 7.62 TOBR, again before conversion to A2...... Californication gun regulations.... Grrrrrrr!!!!!! I have a lot of re-sighting in to do and ammo testing to do on several weapons. However, this does free up a variety of carbine buffers to play with on the Colt (Previously registered assault weapon). Once I finish the conversion of the 6.8 to A2, that will free up a JP tuned carbine spring and I will have a standard buffer, an H buffer, an H-1 buffer and an H-2 buffer to try out.... |
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I feel foolish...somehow or another (I did it) my ammo in one of my 50 caliber cans got mixed up...I had PMC, Remington and Winchester all mixed up. I jus finished sorting 750 rounds...all .223
I believe in order, Winchester is the highest and PMC is the lowest in power...might account for some of the feeding issues. Is my power order correct? Will take all three to the range this weekend and give them a try. 77 |
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I thought I remembered seeing somewhere that Larue didn't recommend PMC ammo. I did a quick search and found that someone in another thread said:
"John M. in the LT shop told me that they don't like PMC much for LT rifles." - https://www.ar15.com/forums/t_2_219/261112_.html&page=1 Not sure if that's correct or still the case, but it might be best to avoid PMC if you're having trouble with it. Hope that helps! |
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One round in mag, see if bolt locks back reliably. My guess is it's just underpowered PMC being the issue, even using the white spring.
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I feel foolish...somehow or another (I did it) my ammo in one of my 50 caliber cans got mixed up...I had PMC, Remington and Winchester all mixed up. I jus finished sorting 750 rounds...all .223 I believe in order, Winchester is the highest and PMC is the lowest in power...might account for some of the feeding issues. Is my power order correct? Will take all three to the range this weekend and give them a try. 77 View Quote http://closefocusresearch.com/calculating-barrel-pressure-and-projectile-velocity-gun-systems You might be able to find more specific information on the link above. The pressure difference between the 5.56 vs .223 ammo helps explain why breaking in your OBR with 5.56 ammo works best. Happy Shooting everyone. Congrats on OBR heavy inbound. My glass recommendation for it would be Nightforce ATACR with MIL-R reticle http://www.nightforceoptics.com/atacr/4-16x42-f1 in an LT-104 mount. |
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http://closefocusresearch.com/calculating-barrel-pressure-and-projectile-velocity-gun-systems You might be able to find more specific information on the link above. The pressure difference between the 5.56 vs .223 ammo helps explain why breaking in your OBR with 5.56 ammo works best. Happy Shooting everyone. Congrats on OBR heavy inbound. My glass recommendation for it would be Nightforce ATACR with MIL-R reticle http://www.nightforceoptics.com/atacr/4-16x42-f1 in an LT-104 mount. View Quote View All Quotes View All Quotes Quoted:
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I feel foolish...somehow or another (I did it) my ammo in one of my 50 caliber cans got mixed up...I had PMC, Remington and Winchester all mixed up. I jus finished sorting 750 rounds...all .223 I believe in order, Winchester is the highest and PMC is the lowest in power...might account for some of the feeding issues. Is my power order correct? Will take all three to the range this weekend and give them a try. 77 http://closefocusresearch.com/calculating-barrel-pressure-and-projectile-velocity-gun-systems You might be able to find more specific information on the link above. The pressure difference between the 5.56 vs .223 ammo helps explain why breaking in your OBR with 5.56 ammo works best. Happy Shooting everyone. Congrats on OBR heavy inbound. My glass recommendation for it would be Nightforce ATACR with MIL-R reticle http://www.nightforceoptics.com/atacr/4-16x42-f1 in an LT-104 mount. Snipert. Thanks...picked up the OBR today. It is great. Just got home and getting ready for a second look at. Will update a post I already have started on it. I looked thru a ATACR this weekend and it is clear. But, a want to watch the weight. Picked up a box of Fderal X855, 62 grain green tips today to run through the OBR. I have a feeling it is the PMC. I had a few issues a few years ago with PMC in one of my LMTs... Thanks, 77 |
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Last Update:
Found the issue, it is Winchester White Box .223 from Walmart Just got back from the range, last sight in of the Accupower, using 77 FGMM ammo, at 50 yards, 7 rounds essentially in the same hole. Rifle cycled perfect, then put in a mag of the WWB, two shots and short stroke. Cleared, ran some more FGMM, no issues, back with WWB, same magazine, three rounds, short stroke Gave the guys shooting next to me the WWB I had left. 77 |
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Last Update: Found the issue, it is Winchester White Box .223 from Walmart Just got back from the range, last sight in of the Accupower, using 77 FGMM ammo, at 50 yards, 7 rounds essentially in the same hole. Rifle cycled perfect, then put in a mag of the WWB, two shots and short stroke. Cleared, ran some more FGMM, no issues, back with WWB, same magazine, three rounds, short stroke Gave the guys shooting next to me the WWB I had left. 77 View Quote Happy to hear you sorted it out. Pics of your set up target etc would really add to this post. |
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