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Page AR-15 » Rimfire and Pistol Calibers
AR Sponsor: bravocompany
Posted: 8/1/2009 6:17:05 AM EDT
I have a Colt style 9mm AR; 7.5" barrel, Colt bolt, C Product mag block, Spike heavy buffer, Wolff heavy spring, and C Product 32 rnd mags.  The LRBHO will not function.  If I hold the charging handle back and actuate it myself, it will hold.  If I insert an empty mag and pull back on the charging handle the bolt catch will not pop up.  It will not work when actually shooting as well.  No other problems except for the occasional round nose diving out of the magazine, and the bolt jamming against it so hard that the bullet crams back into the casing.  Could the bolt and spring be too heavy or too much tension?
Link Posted: 8/1/2009 6:50:04 AM EDT
[#1]
Most likely it's your CProducts mag follower. It sits lower in the magazine and doesn't actuate the bolt catch when empty. If you try using a Colt/Metalform mag, you shouldn't have any problems. What you might want to do is disassemble the mag and file of the swept up lip of the follower on the left side if you are looking at it from the rear. Just file it flat. I did this mod to mine last week and it holds the bolt open now. I haven't done a function test (live fire) yet but plan to in the next few weeks. Just hoping I don't have any reliability issues with the mag. If anything, it's just the follower which can be easily replaced.
Link Posted: 8/1/2009 9:13:27 AM EDT
[#2]
Does the lower have a .223 bolt catch or a 9mm bolt catch?  

The 9mm is longer to reach across the mag block to the follower––a .223 catch won't reach far enough.
Link Posted: 8/1/2009 9:56:27 AM EDT
[#3]
Quoted:
Does the lower have a .223 bolt catch or a 9mm bolt catch?  

The 9mm is longer to reach across the mag block to the follower––a .223 catch won't reach far enough.


The C Products mag block has a catch built in to it that activates the normal 5.56 bolt catch.
Link Posted: 8/1/2009 12:47:05 PM EDT
[#4]
Are you using a rifle or carbine recoil spring?  Is this a pistol or an SBR?



Link Posted: 8/1/2009 1:23:13 PM EDT
[#5]
I think the problem could be the block, not the magazine.  With my Rock River block, my CProducts magazines ALL activate the bolt hold open every time.  But I've heard pretty harsh things about the CProducts block, things like they aren't sturdy enough, and in particular that they don't keep all their parts aligned properly.

Can you post pictures of the block as it's installed?  That would put much of this theoretical stuff to rest.
Link Posted: 8/1/2009 4:54:05 PM EDT
[#6]
This is from the C Products site.    It is in reference to the RRA lowers with the RRA 9mm block.


If purchasing a 9mm magazine for use in a Rock River Rifle, you will need to adjust the magazine block .015-.020 lower to function properly in this platform.

If the C Products block is adjustable, drop it down just a hair.


RRA has moved toward a cheaper manufacturing process of using a dedicate 9mm lower now.    That includes using a poorly designed bolt catch/stop.   The end of it sets too high.    If the tip actually were machined to be flush with the top of the lower, like most 223 bolt catches, it would work properly.


Generally C Product mags are great.   But some guns, like the RRA with the integrated 9mm mag well, will not engage the follower on the C Products mags properly.



Link Posted: 8/1/2009 5:40:54 PM EDT
[#7]
Quoted:
Generally C Product mags are great.   But some guns, like the RRA, will not engage the follower on the C Products mags properly.
ANY Rock River gun with their block and CProducts magazines should trip the bolt hold open.  If it doesn't there's a problem with the magazine follower (sometimes the front gets caught on the underside of the feed ramp), or the connecting link at the back of the magazine block, which needs to be properly lubricated.

Link Posted: 8/1/2009 6:32:38 PM EDT
[#8]
Generally C Product mags are great.   But some guns, like the RRA with the integrated 9mm mag well, will not engage the follower on the C Products mags properly.

Quoted:
Quoted:
Generally C Product mags are great.   But some guns, like the RRA, will not engage the follower on the C Products mags properly.
ANY Rock River gun with their block and CProducts magazines should trip the bolt hold open.  If it doesn't there's a problem with the magazine follower (sometimes the front gets caught on the underside of the feed ramp), or the connecting link at the back of the magazine block, which needs to be properly lubricated.


Better now?


Link Posted: 8/2/2009 5:07:13 AM EDT
[#9]
Quoted:
Generally C Product mags are great.   But some guns, like the RRA with the integrated 9mm mag well, will not engage the follower on the C Products mags properly.

Quoted:
Quoted:
Generally C Product mags are great.   But some guns, like the RRA, will not engage the follower on the C Products mags properly.
ANY Rock River gun with their block and CProducts magazines should trip the bolt hold open.  If it doesn't there's a problem with the magazine follower (sometimes the front gets caught on the underside of the feed ramp), or the connecting link at the back of the magazine block, which needs to be properly lubricated.


Better now?




I don't have any experience with the integrated Rock River guns (not many people do), so I can't speak to that.  Obviously there's a lot of difference between that and a gun with a movable magazine block, and being able to tweak things a bit here and there has its advantages.

Sorry to come off harsh...
Link Posted: 8/2/2009 8:08:23 AM EDT
[#10]
Quoted:
I don't have any experience with the integrated Rock River guns (not many people do), so I can't speak to that.  Obviously there's a lot of difference between that and a gun with a movable magazine block, and being able to tweak things a bit here and there has its advantages.

Sorry to come off harsh...



Hey, that's OK.   I tried to be clear.   But, after reading your reply, I did see room for improvement.  

I have one of the newer RRA  9's and have checked a few other new ones out.   It is the dangest thing.   The bolt catches/stops look like they were machined by moneys and they feel like they have a 10 pound trigger spring.      They are OK, but are clearly going to need work.   They are not close to the gun they used to be.   Maybe the huge rush on AR's the last year has inspired them to take short cuts.    I don't know.   But, I know I like the previous production guns much better.

Link Posted: 8/2/2009 11:45:21 AM EDT
[#11]
Quoted:
Quoted:
I don't have any experience with the integrated Rock River guns (not many people do), so I can't speak to that.  Obviously there's a lot of difference between that and a gun with a movable magazine block, and being able to tweak things a bit here and there has its advantages.

Sorry to come off harsh...



Hey, that's OK.   I tried to be clear.   But, after reading your reply, I did see room for improvement.  

I have one of the newer RRA  9's and have checked a few other new ones out.   It is the dangest thing.   The bolt catches/stops look like they were machined by moneys and they feel like they have a 10 pound trigger spring.      They are OK, but are clearly going to need work.   They are not close to the gun they used to be.   Maybe the huge rush on AR's the last year has inspired them to take short cuts.    I don't know.   But, I know I like the previous production guns much better.

The connecting link in a RRA magazine block either has no spring or a very very mild one, which means the only real spring tension fighting the follower comes from the rifle bolt stop itself.  I can't imagine why they'd put a heavy spring on that part...it doesn't make sense to design it that way.  Must be some sort of "oh we're in a rush" action, using the wrong spring because that's what they had on hand, or something like that.

Edited to fix wording...

Link Posted: 8/2/2009 12:21:34 PM EDT
[#12]
I think it is probably the block.  I went out and shot two mags out of it yesterday and had several FTF and FTE, mostly at the beginning of the magazine.  However both mags tripped the BHO now.  I guess I'll save up for a Hahn unless there is a fix for the C Products block.
Page AR-15 » Rimfire and Pistol Calibers
AR Sponsor: bravocompany
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