Question; is there a buffer low weight minimum, not to pass or go below?
I guess if positive cycle rate performance incurs carrier bounce its time to open the port?
I’m currently at 2.6oz buffer (using Strikes’ Optima Buffer kit for weight mgnt.) Started with 3.28oz, then 3.03oz.
My brass (M855 DRZ penetrators, 556 62g, and some Armscor 223 rem 55g) ejecta have gone from 5 – 530 up to about 330 o’clock and from not cycling new rounds to consistent feeding, with Brass, but Steel (Tula 55g) is still not auto feeding.
I know this forum is M4Carbine.com, but I’m looking for as many "experts" as possible for help with cycle rates on a 20” piston build. Using a Adams Arms rifle length kit on a Faxon, it is so far been performing under gassed. I read through the STICKYs here re short stroking and Buffers…all great reads and confirming science/known engineering. Rather than go straight to opening the port, Im playing with the other end of tuning.
The port on the 20″ Faxon, 556 I have is 0.078. I confirmed with Adams Arms responded that their rifle kit should operate with a 0.098 port. So I know Im under-gassed. Machining and drilling holes is pretty straight fwd but not reversible. I might want to use the barrel for a DI rig eventually if this piston party flops.
Considering the timing to pressure on the bcg is a lot different on pistons, I will re-evaluate going lighter rather than heavier. I started with a standard, 32 coil springs and 3.06oz buffer and full open adjustable block. The performance progress trajectory I’ve gained going to a lighter buffer spring and weight show positive feed back.
I will also look into the bolt lock test, but I’d have to switch lowers. This rig is a Commiefornia special running a Juggernaut Tactical kit….these replace standard bolt catch for a mag lock and release.
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