Help with FTF in a 10.5" LMT with suppressor

[m4_556]

Hi. I have a LMT MRP CQB setup that has 14.5 and 10.5" barrels. I run the 10.5 for HD and have historically kept an A2 FH on it. Today I installed a brake mount for my AAC m4-2000 and test ran 100 rounds. I had 3 FTFs which is wild considering with a H2 buffer and well-lubed BCG I've never had more than 3-4 malfunctions after 5000 rounds. Any advice? I'm scared an H3 buffer won't run a 14.5 setup well. Thanks for all the advice.

[An Undocumented Worker]

Perhaps you may want to look into running an A5 reciever extension/buffer system.

Basically it allows you to run the rifle spring and buffer with collapsable stock in a package that is only 3/4" longer than a carbine extension.

https://www.m4carbine.net/showthread.php?t=95328

http://www.vltor.com/emod-a5.html
And no you do not have to use the Emod stock if you do not want to. Any milspec stock will work.

[Cincinnatus]

What ammo and mags are you using? Same result with all ammo/mag combinations? We need more info to diagnose. Is the bolt locking all the way open on last round?
Does the weapon function with same ammo/mag combos unsuppressed? What ammo were you using?
You might also check out C4Grant's thread on "the best Suppressed Carbine ever" for some ideas on what may be the problem.

[Iraqgunz]

My set up is very similar (BCM 11.5 w/ AAC M4-2000) and I went to an H3 and had 100% function. Then I switched later to the A5.

The other alternative which will probably be my (future) standard is the Vltor A5.

[dudshep31]

I run a 10.5 mrp with the m4-2000 and an H buffer. Flawless through 1500 rounds.

[m4_556]

Thanks for all your replies. Ammo was new production m855 (2011) date code, proven functional p30m pmags, and yes; would lock back the bolt. Right now I'm thinking the easiest route would be to try an H3 buffer. Edit - forgot, yes always functional unsurpressed.