Which buffer/spring?

AR/M4 AR General Discussion
1

So I bought an Armalite M-15, mid-length before I new better, and it seems to be over-gassed. With notoriously weak PMC, it ejects around 2:00, which according to a chart another member posted indicates over-gassed. However, the occasional round will only travel about a foot, landing in my right elbow,(lefty).

I’m thinking about an H or H2 buffer and a Sprinco heavy(red) spring. Am I headed in the right direction?

When I have the funds I plan on upgrading to a BCM, but a new upper/rifle is not in the budget for now.

Thanks in advance for any advice.

2

Sounds like you are going down the right path - you really want the brass to be ejecting perpendicular to you - over gassed flys forward, under gassed trickling out and to the rear.

I would stick with buffer weights before playing with springer - IMHO.

3

Since it is a middy, I would go with an H buffer and the BLUE springco CS spring.

C4

4

You can’t go wrong with Sprinco springs, that’s for sure. I’ve used their Red spring and 5.4 oz buffer in my S&W 5.45 upper and it barely recoils (and doesn’t short stroke).

My experience with their Machine Gunner Lube has been very positive as well. It tends to “stay put” better than Slip 2000.

5

+1

The Springco springs are awesome, but if you go stronger than the blue in a middy, you may get hang-ups. CS springs are GTG for a LONG time, btw.

6

Grant,

Thank you for the reply. Is the springco CS spring listed on your site the blue?

Also, what about the occasional short ejection? While I’m not a wimp, I would prefer to avoid brass burns on my support arm.

7

Yep, blue.

No idea on “short ejection.”

C4

8

Armalite installs a CRANE type o-ring in all their AR’s and BCG’s.That said the o-ring they use is very stiff composition in comparison to say Colt or LMT.IMHO the extractor tension on the assemblies is excessive for a midlength.
If the o-ring is still in place try removing it and see if the ejection direction shifts and or improves etc…