KNS is who makes the retaining pins I use. Solid w/split ends.
https://www.joeboboutfitters.com/KNS-Perma-Pin-Firing-Pin-Retainer-p/kns-perma.htm
That is the one for the AR15 but they also make them for the large frame guns.
The 140 American Gunner shoots well in my creedmoor as well. The cheap Winchester 125 gr also shoots well. Not as well as the American Gunner but still sub MOA.
Glock 17 slide and internals. Lower parts kit for 80% lower. Still waiting for the spring that holds the takedown lever in on my g23 build. Damn thing is here somewhere but I can't find it. Those little springs are out of stock almost everywhere.
More Grendel mags and Glock mags for the 2new pistols.
Was going to buy some more Grendel ammo on Gunbroker. The American Gunner Grendel ammo I paid $139.00 for 200 rnds last spring got to over $3.00 a round on an auction. NO THANKS. Don't need it that bad.
The PSA bcg,'s are dpms pattern. Ballistic Advantage barrel fit in my PSA upper just fine. Rail was dpms high from local gun store. Yes Aero is easier to find stuff that works. The PSA upper will probably only fit a PSA lower.
Glad you got it running right. I think the only thing on my PSA that is still original is the upper and lower receiver and take down pins. And the bolt carrier group but it has a different ejector now.
Also check the ejector face. Is it square or rounded ? My creedmoor had to have a rounded ejector before it would run right.
https://www.kakindustry.com/lr-308-parts/308-upper-parts/308-bcg-and-spare-parts/kak-bcg-ejector-308
Just use whatever recoil system and stock you prefer. The uppers barrel length has nothing to do with the stock configuration as long as the gas port and tube are set up properly.