H3 or 9mm buffer for 7.62x39AR?

[castanagajt]

i was wondering which of the three you would pick from:

Palmetto State Armory H3 buffer
CMT H3 buffer
Rock River Arms 9mm buffer

20inch barre
Rifle- lengthl
regular F-marked front sight/ front gas block
AR15––-6 pos. collapsible stock
m16 auto carrier
regular AR15 spring

*6.5oz buffer with CAR15 spring causes it to short stroke.
*6.5oz buffer with heavier car15 spring still short strokes.
*heavy spring with Spikes Tactical ST-T2 causes it to double feed.
*CAR15 stock spring with Spikes Tactical ST-t2 work the best but only 40% reliable. Round tries to go in but spent casing is almost out.

I tried my semi auto carrier with the stock spring and Spikes Tactical ST-T2 and it jams evey other round.
The best combination is the Full auto carrier/ stock CAR15 spring/ Spikes Tactical ST-T2
Magazines are working fine. They are Franken mags but I may try ASC 7.62x39 mags some time.
When it does cycle correctly it is smack at the 3 o' clock.

i was wondering which of the three you would pick from:

Palmetto State Armory H3 buffer 5.4oz––––––––––$35.00
CMT H3 buffer 5.2oz––––––––-$40.00
Rock River Arms 9mm buffer 5.5-5.6oz––––$25.00––-no internal weights so reciprocating mass is less than the 5.4oz

I am hoping you all can help me out. Thanks So of the three which would you pick?

[tenmile]

Great question! From what I have read here there seems to be considerable difficulty in making the 7.62x39 reliably function on an AR platform. Non the less I applaude your efforts. It is a great little round with excellent penetrating capabilities. One would think that a standard mil spec spring would do the trick

[eldogg]

it's most likely a gas pressure issue. i am running a carbine barrel, standard buffer and a ar15 bolt carrier, and it was short stroking. i opened up my gas port to .0938 and i haven't had any more issues.

[Todd.K]

The 9mm buffer is only good for saving a few bucks and being heavy enough for the blow back operation of the 9mm AR. It lacks most of the buffering effect of the sliding weights so unless you are running a 9mm and can't spare the $20 difference I'd always choose the H3.

You are describing several different malfunctions so I don't think you are going to have perfect function by changing out the buffers.
You have short stroke, double feeds and failure to eject.
Double feeds (two live rounds) are a magazine failure.

You need to work on one thing at a time. Put one round in the mag or better yet load one round in the chamber and then inset an empty 5.56 mag, then shoot and check for lock back.

[rsilvers]

Sadly, even I you get it working, the bolt may only last a few hundred or a thousand rounds. I tried and tried and gave up.

[castanagajt]

I hope when I get the H3 it will work better. The 7.62x39 is a pretty violent round it really is beating on the front take down, flattenig the bumpstop of the buffer, and rendering a carbine spring out of spec quickly.

The good part is an H3 buffer is coming in from GRtactical.com, and I was able to find a late generation C- products magazine which I don't own or tried any at this time.

If worst comes the worst and I need to do a gas regulation do Noveske has a SwitchBLock for me?

I really appreciate the help all.

[rsilvers]

Then your gas port may be too large. You can fix it with a new barrel or an adjustable gas block. Hoe far does the brass eject?

[m4forme]

have you thought of trying a fixed stock with a standard rifle buffer...

[castanagajt]

Originally Posted by m4forme

have you thought of trying a fixed stock with a standard rifle buffer...

It is a consideration but not at this time because we like the look of the collapsible stock. We are however, considering a VLTOR A5 extension with the A5 buffer if we are getting steady positive progress from going with an H3 buffer, then an adjustable gas block, and that would be last.