Buffer Suggestion

[ALhunter]

Hello, I have a 20" criterion upper coming from PF without adjustable gas block and just wondering what buffer/spring I should use. I plan on using a 6 position collapsible stock for the build. If JP SCS would I use standard or H2. For cheaper options what do you recommend?

[grayfox]

Mark would have a good suggestion.
With a rifle length gas system start with the normal carbine, maybe go up to an H or the Kaw tungsten...
I don't like the original sproing but not wanting to go into the SCS cost arena, so I've been using the JP centerless ground springs. Very quiet and smooth. About 20 bucks if I recall. Get the proper buffer tube length.
'Course you could get a not-too-expensive low-profile adj GB if you wanted to... look at them on joebob's.

[Kswhitetails]

You should be fine with carbine, H2 if things are hairy. It should cycle fine once things smooth out. Are you going to suppress it?

[ALhunter]

It will not be suppressed. I emailed Mark as well just hate bothering him with each little question I have as it is my first time piecing an ar together. I appreciate you guys taking the time to educate me.

[mdram]

let us know what he suggests.
well at least let me know , as hes building me a bartlein atm

i do already have the kaw tungsten buffer

[A5BLASTER]

I would start with a carbine buffer and a jp carbine spring. If the carbine buffer isn't enough KAK sales tungsten buffer Wright's that fit standard buffers. Order up 3 of them and try changing one at a time until you get what your wanting.

Are just get a cheap adjustable gas block from wojteck and dial it in and be good to go. If you go adjustable gas tune it with wolf fmj ammo. It is the weakest ammo for gas pressure. If set with it all other ammo will be gtg.

[ricsmall]

All my rifle length builds from 18”-22” use a rifle buffer in rifle configuration, or H2 if using carbine stock configuration. I couple this with adjustable gas block as well.

[LRRPF52]

I took 3 x 20" Grendels to the range for accuracy testing one day.

One had rifle RET/rifle buffer and spring
Next had carbine RET, carbine buffer and spring
Next had carbine RET, H2 buffer and spring

All of them ran just fine, and it was hard to tell the differences between them. I think the 2.9oz carbine buffer cycled a little faster, but it was negligible.

I've also built and tested A5 length RETs and buffer/spring combos, which handle very nicely, more like a rifle RET/rifle buffer/spring combo.

This was all with 123gr factory Hornady A-MAX and SSTs, as well as some 123gr SMK hand loads.

For carbine RETs, an H through H2 might feel better for you on a 20".

When you shoot lighter grain loads of 100gr or less, it might be better to have a 2.9oz buffer with RLGS 20" guns.

[ALhunter]

PF got back with me and said they suggest using the JP SCS2 Standard or for a cheaper route standard carbine spring and buffer

[Happy2Shoot]

Just have him put on an adjustable gas block.

[-Justin-]

Adjustable gas block is the best option, my 20" runs a standard carbine buffer with adjustable gas, it would be over-gassed without the adjustable block. If you want to run the JP I'd start with the heavier version.