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Page AR-15 » Rimfire and Pistol Calibers
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Posted: 3/11/2006 7:03:32 AM EDT
I recently received my RRA 9mm upper.  I am using a Hahn bottom loading magazine block.  The lower is a M-16A2 sans auto sear and full-auto selector (work lower).  Magazines are new Colts.

I've had two range trips and the gun would not run on either.  Initially, I was using Winchester 124 grain white box.  Today, I brought along some Winchester 115 gr white box and some NATO spec rounds as well.  

From my intial impressions I thought the gun might be short stroking so I though the hotter ammo would solve the problem.  I also pulled the bolt, wiped, and lubed it and cleaned the powder debris from the upper.  None of this helped.

The gun has two major problems.  The first only showed up today.  Using a mag well hold, the Hahn would become loose and apparently cause double feed problems.  The Hahn was slowly slipping out to the degree that the magazine release had significant tension on it.  Not using a mag well hold seemed to solve this problem.

The major problem is a failure to eject.  It is impossible to fire more that 8-10 rounds without the gun malfunctioning.  Typically, the spent case is pointing straight out the ejection port with the fresh round jammed underneath it.  Other times, the spent round is pointed up at roughly a 45 degree angle and tied up with the fresh case.   These tend to really tie up the gun to the point that you cannot cycle the charging handle.  Clearance requires tapping the buttstock on the ground while pulling the charging handle to the rear.  As an odd note, roughly 85% of the time, the last round fired stays in the action after the bolt locks open.  I've also had some odd instances of a fired case making it past the ejector and ending up in the firing group which is an interesting clearance procedure.

Throughout the range trip, I cleaned and lubed the gun.  The best it ever ran was 15 rounds of Nato ammunition immediately after a good cleaning but that was the only time that so many rounds were fired without problems.

I have been able to simulate most of the ejection problems by running the charging handle slowly.  The bullet spins in the action and goes nowhere.  If I run the charging handle hard, the rounds eject as they should.  

As a final note, the lower I am using is NOT the lower the upper will ultimately be used on.  I plan on having the bolt ramped and installing a neutered M-16 hammer in my personal gun.  

Any suggestions on fixing this problem?  Should I wait 'til the bolt is ramped and I'm using the upper on the intended gun to solve the problems.
Link Posted: 3/11/2006 8:09:27 AM EDT
[#1]
RRA has a known issue with thier extractor pin.   Chances are your extractor is not holding the empty case tight enough for the ejector to give it a good wack.  I think most folks are swapping them for a roll pin from Lowes.
Link Posted: 3/11/2006 10:08:33 AM EDT
[#2]
The Hahn Bottom Adapter is held in with tension....you can crank down on that screw as hard as you can.....it won't damage the receiver.  This adapter was meant for switching back and forth between calibers but it still shouldn't be moving when installed.  

The FTE problems you are having sounds like the typical weak extractor/extractor pin issue......pretty common malfunction.
Link Posted: 3/11/2006 12:46:44 PM EDT
[#3]
IF the gun is a RR I would be careful cranking down on the screws. I have read about someone cracking there lower with the block set screws. Just take them out and add some BLUE loctite. Beowulf is right about tht e extractor pin coming loose . Mine has not so far, but the fix is easy.
Link Posted: 3/11/2006 3:49:23 PM EDT
[#4]
How do I know if the pin is causing the problem?  I checked an the ejector pin seems centered in the reduced section of the channel in which it should fit.  The roll pin does have a huge gap, ist this the problem?  Do I just replace the pin and if so with what size?  I checked this forum and found similar problems but no hard explanation of a fix.  

thanks in advance............
Link Posted: 3/11/2006 5:16:18 PM EDT
[#5]
HomeDepot and find a rollpin Look at this link HERE
Link Posted: 3/16/2006 6:48:20 AM EDT
[#6]
I had the same problem.  Check HERE.
Link Posted: 3/18/2006 2:09:49 PM EDT
[#7]
I was back at the range today, trying to sort out the problems I've been having.  First, I went to the local hardware store and picked up several roll pins.  On slightly larger than the factory and the other substantially larger than the factory.  I swapped the roll pin without trouble and went to the range.

The rifle ran well for the first 150 rounds but then it started to puke as it had before.  I took it back to the office, replaced the roll pin with a spare I had, and tried again.  The rifle continued to puke.  I returned, tried to install the next size larger pin I had but it would not fit.  Next, I pulled the extractor, cleaned it and "tweaked" it.  Returned to the range and the rifle continued to puke.  Pulled the extractor again and tweaked it some more.  The rifle continued to puke.  (I tried three different Colt mags and none worked better than another)

I this point, I'm not sure what to try next.  I believe I may be able to get my hands on a Colt 9mm SMG bolt.  If I can, I plan on swapping it in and seeing if it runs the gun.  If I'm still having problems, I'm also considering putting the entire subgun uppper on the current rifle and seeing if it runs with the Hahn magazine block and Colt magazines.

I had a camera with me so I took pictures.  My malfunctions all seem to be issues of ejection/extraction.  If one "style" was most common, it would be this one:


Below are some other pictures.  The case behind the ejector is typically the result of trying to clear a malfunction.




Link Posted: 3/18/2006 2:23:20 PM EDT
[#8]
Send this over to the Full Auto section since yo uare using a FA gun . Maybe they can help U better and faster. Good Luck. OUT. Tuna
Link Posted: 3/18/2006 3:54:26 PM EDT
[#9]
how about a pic of the lower showing the top of the magwell block, w/ and w/o the mag installed. have you tried ejecting a spent case by hand?
Link Posted: 3/18/2006 5:18:56 PM EDT
[#10]

Quoted:


I this point, I'm not sure what to try next.  I believe I may be able to get my hands on a Colt 9mm SMG bolt.  If I can, I plan on swapping it in and seeing if it runs the gun.  If I'm still having problems, I'm also considering putting the entire subgun uppper on the current rifle and seeing if it runs with the Hahn magazine block and Colt magazines.



I think you need to look here, and verify that the ejector finger is positioned correctly... COLT® by design left little room for error in placement of ejector for maximum contact with case (what little there is)...  Re-assemble rifle, and slowly pull bolt to rear, and watch ejector appear at bolt face.

You want it to ride as close as possible to center, and as high as possible to get maximum contact with case when it taos the case....   In the pic, mine ideally needs to go "up slightly, but mine runs 100%, so I not fart with it, and it is already close to center without actually rubbing bolt.

Link Posted: 3/19/2006 12:19:18 PM EDT
[#11]
I checked and there is a gap between the ejector and the bolt.  I'm not sure if it is "too much" or not.  Below is the best pic I could take:



Should I tweak it up some?  If so, what's the best method, "best" being no damage?
Link Posted: 3/19/2006 12:32:21 PM EDT
[#12]
Also, I just pulled the mag block from the weapon.  Examination found a lot of "slop" in the ejector.  Specifically, the slop is mostly side to side.  How much, if any, slop should there be and can you adjust the slop out of the mag block?

Link Posted: 3/19/2006 2:18:46 PM EDT
[#13]
The Hahn Adapters have that 'slop' built in......to eliminate friction with the bolt slot.  

Tighten that tension screw in the adapter has hard as you can...it is impossible for that tension device to damage your receiver.

You are having EXTRACTION problems.  Specifically it may be one or more of the following issues:
weak extractor
bad extractor incorrectly made
shitty pin
bolt may have pin hole in wrong location relative to bolt face
Link Posted: 3/19/2006 2:49:30 PM EDT
[#14]
Some answers.  Today, I took my mag block apart and tried to see if there was any adjustment to eliminate the slop in the ejector.  I retightened the bolts hard and I still had slop.  To test my theory, I took the block apart again.  I took three (3) tiny pieces of notebook paper (don't laugh) and placed them on the ejector so that they sat between it and the magazine adapter body.  With all three in place, the bolt hold-open would not actuate but the ejector had no slop in it.

I took the rifle to the range and ran it.  It worked perfectly, boringly perfect.  I fired a mix of NATO spec ball and 124gr Winchester white box without a problem.  Eventually, even the bolt hold-open began to work.  The gun continued to run perfectly.  For three hundred rounds, I had two malfunctions.  The first was a double feed that occurred the first time I loaded a new magazine to near-capacity.  The second was a classic failure to eject with the bottom of the case facing out.  By my count that's 1 malf in 300 rounds which is acceptable in my mind since this is a training gun.

I'm going to contact Hahn and see what they say about the problem.  I wonder if the relief cut on the side of the mag adapter is just a little to deep to work properly.
Link Posted: 3/20/2006 3:37:35 PM EDT
[#15]
I think designing an ejector with slop is a terrible idea.  They can usually be bent to position if neccessary, but obviously slop will make that difficult if not impossible.   You may want to get a calipers on three pieces of that paper, and replace that with that thickness of stainless feeler guage. dremel cut and drilled for the pin or whatever is holding the ejector in.  
Link Posted: 3/28/2006 1:07:14 PM EDT
[#16]
I am having the same exact issues shown in these pictures regarding extraction of fired cases. I had no idea a 9mm casing could fit into so many interesting places of an AR action.

I had one spent casing blocking the hammer and another got between the charging handle and bolt.

My ejector is already very high, in fact I had to take 5 thousands off for the bolt to properly cycle by hand.  And it still contacts a little bit based on the shiny spot free of powder residue.

However, it is not centered, and is on the far side of the bolt face, although I think it doesn't rub on the side.  How to adjust this thing?  Bend it?

I believe its an ASA block.  RRA Upper.  Funny thing is I ran a couple mags with no problems, then it just started choking every couple rounds.  Should I replace the extractor pin before I do anything to the ejector?

***a half hour after writing this, I was breaking it down and took a look at the extractor, I thought it was sticking a little too far out so I went to pull on it and it came out.

Sure enough the pin and worked itself freeof the extractor.  I cannot believe RRA hasn't solved this yet, it was purchased last week.  Two things, the pin sucks and it isn't long enough.  It can come free of the extractor yet still be inside the bolt body so its not even obvious when it starts to work itself free.  Plus if it was longer, there would be a chance the upper would keep it from coming out, at least on the top side.

I am upset with RRA, they ruined a range trip and I wasted two boxes of ammo trying to figure this thing out.

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