Aero Precision M5 .308 Short Stroking

[RBivs96]

I have a complete M5 .308 18” upper from Aero Precision and have shot it several different occasions and had issues with it short stroking, weak ejection patterns (if it does eject), and failure to eject. I have a M5 Carbine length lower on this build that I bought from Aero as well. What could be causing these issues? The most I’ve ever had it work was 5 rounds after the bolt carrier group was drenched in gun lube. I’m at a loss here as it is my deer rifle this season and I’m not sure what else to do to try to correct this problem. Please help.

[Armed Eye Doc]

Welcome to the forum.

There are a few things that can cause your problem.  I will point you to this thread to let you know what kind of info may be asked of you.

https://forum.308ar.com/topic/19170-waterboarding/

[shooterrex]

Welcome from KY. We need a lot more info to be able to help you.

The waterboarding thread is a good place to start.

[98Z5V]

Here's another thread with some info that directly pertains to what's going on with your gun:

 

[DNP]

Welcome from San Diego. Keep thick skin as the questions fly…and they’ll share the same tidbits that seem to make every gun run. If it works out to be something out of the norm (and those odds are small) and you can keep from feeling like you’re being attacked (which you are not, some folks are just very straight to the point) they’ll keep at it until it functions. Everyone here likes to see reliable guns putting smiles on faces. 

[98Z5V]

28 minutes ago, DNP said:

 they’ll keep at it until it functions. Everyone here likes to see reliable guns putting smiles on faces. 

^^^  This is the bottom line, right here. 

[RacerX]

You might also want to include what ammunition you are shooting.  That's not one of the waterboarding questions.

[DNP]

After watching this show for a handful of years, I’m gonna throw $20 down on the “it’s all in the recoil system” pile and I’ll cover my ass with $10 on the gas port size….but I’m doubting that will be it. It’s almost a sure bet it’s one of the two or a combo and it’ll be functioning fine in no time. 

Edited November 9, 2021 by DNP

[shooterrex]

Aero's 308 carbine buffer is only 3.8oz. 5.5oz range seems to work best.

Bet it is the recoil system.

This recoil system works.

https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01&ReturnURL=/Armalite/Product-Category/AR10-Parts-Accessories&Category=4eeff98b-d9a6-40fd-be6b-ab2e44ec1080