Re: lower pack kits lpk
I've built lowers with RRA, Stag, PSA, and DD lpks. And only ever had an issue with a Stag in a Sabre Defense lower. It appeared to be a case of tolerance stacking between the two and was quickly remedied.
I've also sold hundreds of DD lpks, without issue or complaint.
Of those mentioned I liked the DD the best, but certainly not enough to justify a $125 premium over the others.
Brownell's has a Colt lpk minus the pistol grip and fcg (they call it a Rifle Accessories Kit). High quality parts and allows you to pick your own grip and trigger. I'll probably go this routed with my next build.