So I plan on building a 8" 300 Blackout with an Adams Arms 300Blk piston kit. I spoke to a rep from AA and they said their piston kit is designed around typical mil spec buffer weight and spring. They also mentioned a reduced power buffer spring may be needed depending on the back pressure of the suppressor. So I'm hoping to receive some insight from anyone with knowledge/experience in this. I was hoping to run the JP silent capture kit. For use with subs and supers, suppressed and unsuppressed. But, I know that "general purpose" and "all encompassing" things generally do not work out as planned. Any help is appreciated. Thanks!

There really isn't a magical formula. You can start with some guidance...but then you still might have to tinker. I know BCM recommends an H buffer for supers and a carbine buffer for subs but once you add in different buffer systems, suppressors, etc. anything can happen. I've seen setups that should be fine on paper not run and vice versa.

I had an 8” w/ the AA kit and a JP SCS. Worked great with the white spring & 3 steel weights. Wound up selling it on the EE to try something new.

Yeah. I was thinking about getting the JP kit with the various springs and experiment with them.

How did it function? Any issues? Did you have an H or HH kit?

You mean the SCS? it was a carbine (standard) kit (I bought the one with the spring pack).  I think they sell it in two versions - carbine and H2 equivalent.

It shot just fine actually, with zero issues once I swapped the barrel.  My original barrel was junk (CMMG) and was shaving projectiles and blowing plating and coating up into the piston cup causing it to seize up.  Replaced with a Seekins and it was perfectly fine for the 200-250 rounds I shot through it.  Didn't keep it long. Although I loved the reliability (zero issues in 250ish rounds was the best I've had with 300 BLK subs), I didn't plan on a piston kit originally and the gas block was right under where my hand went.  When the gas vented off it would be very hot on my hand and the rail directly around it.  I'd have just switched the rail but I have a custom cerakote job that I am not paying again to have redone on a shorter rail.

Did you use the low mass BCG? I don't think the heat will be an issue since the monolithic upper I'm using is a quad rail with heat shields on the inside.

Yes it was a low mass carrier...If I recall correctly AA only offers the 300BLK kit with a low mass carrier.