Will this work for a simple PSA MILSPEC lower ?
Yes.
The “large pin” lowers were an effort by Colt in the ‘80s to offer a “Civilian Only” or “Commercial Spec” AR-15 that no MilSpec parts would fit - particularly FCG. The pin size on those was something like 0.192 dia. (mem’ry here).
It’s been essentially a moot point on non-Colt lowers, especially since the 1994 Ban expired. Everyone is MilSpec now. (for the AR-15)
I have seen exactly one (1) “Commercial/Large-Pin” rifle in my life. (that I know WAS indeed that)
They ARE floating around out there still, so most parts manufacturers add a little LawyerSpeak as a Caveat.
Thanks for the info!
just as an additional note, the MB-25 trigger is one of my favorite triggers. they are awesome and great for the price. back when they were 200 though i’d of never bought one. I got them when they first dropped down to 89.00 each and since then they’re amazing for that price. good luck!!