buffer weight for a 6.5 Grendel?

[LRRPF52]

I used a Spike’s ST-T2 on my first AA 16” barrel build.

I’ve also used standard 2.9oz carbine buffers, H, H2, rifle, and JP SCS.

The Maxim PDW mini pistol buffer with its short, stiff spring and tiny RET works really well on 12” CLGS with the correct port.

I took 3 different 20” Grendels to the range once, all with different buffer weights including 2.9oz carbine on up to rifle.

It seemed like the H2 and rifle buffers supported the best ejection and cyclic rate, but that’s subjective.

Bill A. designed the Grendel to be a drop-on complete upper conversion for your existing AR15, with a key emphasis on gas port diameters matched to the gas system and barrel lengths.

With most factory ammo, it works just fine with your existing lower.

The main outlier I’ve seen reliability-wise is the 90gr TNT loads, both from AA (discontinued) and Federal.

They have always had a tendency to short-stroke the action in some AR15s.

My 12” runs them like a raped ape suppressed, but not unsuppressed.