Over gassed issues? - On an old carbine

AR/M4 AR Technical Discussion
1

This rifle is not my primary but one I build in the late 80’s.

It has been close to 10 years since I shot this rifle.
Unknown brand barrel 1:9 that was an heavy carbine that I had re-profiled to M4, chamber maybe .223 or wylde. I doubt it is even chrome lined.
Bolt is non-MP, carrier AR15, carbine buffer, original recoil spring (might be an old tapco type).
I shot it this weekend with Wolf steel case 55 gr. which ejected in the 1 to 2 o’clock direction and it kicked like a mule. About 20 rounds in I had one primer pop out then I stopped, all ejected steel cases looked normal.
I had been shooting my BCM 18" SPR on the same trip which had little to no recoil in comparison and ejection in the 3 to 4:30 direction.
I did try swapping a H buffer with the carbine buffer at the range and not much of a noticeable change.

Following the range trip I cleaned and checked the headspace. Close on GO and not close on FIELD. The bolt has a newer extractor spring, insert & O-ring, a McFarlane ring and will not collapse on the weight of the carrier doing the ring test. Gas Key is tight and staked but not to standard yet (working on that). The carbine spring is 10.75" but feels weak in comparison to my newer springs.

I plan to replace the buffer with a H and try an new carbine buffer spring and try again. I may swap the carrier to a heavier one.

Anything else to consider or look at? Did I miss something?
Thanks for your time.

2

What length is the carbine spring ? Replacement length is 10 1/16’'.
And yes you would probably want to use an H-buffer.

3

I added to the original post, 10 3/4" on the carbine spring. But it is original and maybe low quality.

4

Roger that along with buffer spring and H-buffer I strongly urge you having the chamber reamed with neds 5.56 chamber reamer a lot of people report that after reaming that wolf runs better.

5

To date, I have never found a 1/9 twist barrel that had the correct GP size (FYI). I am sure they are out there though.

So the odds that it is over gased is very high.

C4

6

Not even Colt? :eek:

7

If not even an H2.

8

Could you please tell me the correct size for the gas port on 16 in barrel carbine gas ststem

9

Or an H3 in this case.

I have an old Nessard barrel like this. It is my beater rifle.

After a PRI Fatboy Gastube, an MGI RRB and a Wolf +10 Recoil spring, it now ejects at 4 O’clock and runs liek it should.

Funny thing, it always functioned very well but had way too much recoil.

10

Heavy Metal have you run a neck / throat 5.56 reamer in your overgassed barrel?

I was under the impression that the Wolf ammo is on the lighter powder side of 5.56 ammo. With that in mind I would be very leary about shooting any full powdered M193 or M855 out of this gun.

Having popped out a primer in only 20 rounds and this rifle headspaces just fine, I am under the thought that reaming for 5.56 may be a solution I need to strongly consider.

On my next range trip I will try a FA carrier with H buffer and a new carbine spring. Since I have all of this on hand, anything else like H2 or H3 buffers would have to be ordered.

11

Colt is about the only 1/9 twist that I have not checked. Knowing Colt though, the GP is most likely correct.

C4