My PA10 gen 2 lower was purchased on Aug 17th, 2017 and came with the standard sized AR15 carbine buffer (weighs 3.7ozs so it's an H1) and the longer PA10 marked tube.
I paired it up with their 18" Stainless 1:10 twist Free Floated upper, an American Defense scout optic mount and a nice inexpensive Bushnell Trophy XLT DOA scope.
I first noticed something was up when the MOE stock wouldn't adjust all the way forward. It was a busy fall, and a nasty wet winter so I never got to test fire the gun until mid February. I fired 8 rounds and then knew something was amiss with the recoil system.
This rifle kicked like a .300 Win Mag from a bench with standard M80C milsurp ammo.
So I 'fixed' it with a Luth-AR MBA1 stock and the rifle length .308 spring and buffer kit.
Going up 2oz and the proper length on the buffer and proper spring rate made all the difference.
I am installing a Superlative Arms bleed-off adj gas block later this week due to intended use with a supressor.
But this thing needs the proper weight and length buffer to be a complete rifle. I was lucky that Primary Arms had a flash sale and I got the stock and buffer kit for basically what the stock costs ($140). Plus it is completely adjustable in every way. Highly recommended unless you have to have a $300 Magpul PRS.