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View Full Version : AR 9mm Bolt Catch Breaking...


coq
11-08-2013, 8:44 PM
It's a DDLES Glock 9mm lower, CMMG 9mm Bolt (moded for Glock mag) and standard AR hammer, YHM 9mm Buffer, factory ammo...

I'm a little stumped. I've broken 2 so far, the last one after only a few rounds (and not on an emptied mag). I've heard of this happening, but usually it's with standard length buffers and upon emptying a mag.

Anyone else have this issue...or better yet, some insight on a fix?

Thanks.

ar15barrels
11-08-2013, 9:42 PM
Excessive bolt travel.
Either get a buffer that is 5/8" longer than your existing buffer, or do something to limit the travel of your existing buffer.
You only want there to be 1/4" more travel of the bolt than is needed for the bolt stop to pop up.
Anything more than that and the bolt is going too fast after it rebounds off the end if the buffer tube and hits the bolt stop that pops up after the last round is fired.

I sell these spacers to solve this problem;
http://www.ar15barrels.com/tech/9mm-spacer.jpg

floorance
11-09-2013, 1:18 AM
Try installing a Seekins Precision Enhanced Bolt Catch, was said by others to help with this exact issue for the DDLES lowers

coq
11-09-2013, 5:46 AM
Excessive bolt travel... ...the bolt is going too fast after it rebounds off the end if the buffer tube and hits the bolt stop that pops up after the last round is fired.

Thanks. I thought I was covering this concern with a 9mm bolt, and my last catch broke prior to the final round in the mag. I will measure.

Try installing a Seekins Precision Enhanced Bolt Catch, was said by others to help with this exact issue for the DDLES lowers

This sounds like a good direction. Maybe there's too much slop in the regular bolt stops. I appreciate the help.

coq
11-19-2013, 7:48 PM
Try installing a Seekins Precision Enhanced Bolt Catch, was said by others to help with this exact issue for the DDLES lowers

Got one...and man the thing is beefy. After the range today, I think it's going to work out.

This DDLES Glock lower makes for a really nice rifle, but for me it took a lot of reading and tweaking...their support is just about zero so I want to thank you guys for your help!

Arnelcheeze
11-20-2013, 10:11 AM
what Randal said, Im running a Spikes 9mm spacer, another CGN'r told me he used a stack of quarters to limit the travel.

http://www.spikestactical.com/new/ss/lower-parts-spikes-st9bs-buffer-spacer-9mm-p-174.html

http://www.spikestactical.com/new/ss/images/prodimg/SLA09BS.jpg

L4D
11-20-2013, 2:32 PM
Not sure if they still make them but spikes makes a heavier and longer 9mm buffer.

xxINKxx
11-20-2013, 3:14 PM
All the spikes 9mm stuff hasn't been available for the past year except for their conversion block.

L4D
11-20-2013, 3:22 PM
All the spikes 9mm stuff hasn't been available for the past year except for their conversion block.

actually Aimsurplus gets them in batches from time to time.
http://www.aimsurplus.com/product.aspx?item=XSTSLA009X&name=Spikes+Tactical+ST-9X+9mm+Stainless+Steel+Buffer&search=spikes

JamesY
11-20-2013, 4:49 PM
I use a stack of quarters. Works fine for me.

coq
11-21-2013, 5:43 PM
I use a stack of quarters. Works fine for me.

Not sure that would have solved my issues, as I started with a 9mm buffer (see OP). Also, I broke a bolt catch with plenty of rounds left in mag, which led me to believe the catch wasn't being held down sufficiently and might be taking a random beating. Hence the further bending/tweaking of the little proprietary actuating thingamajigger and the enhanced catch. Seems to work great now.

I'm sure some come from the factory working just fine...mine was a little off. It even came with the wrong mag catch installed...had to diagnose myself and get a replacement (thank you John @ Rifle Gear).

If they supply Law Enforcement with this stuff, you'd think they to get it dialed in before shipping out. This DDLES is a quality lower, however IMO the internals and weak points could be enhanced without a drastic change. So could the customer service.