Ruger Mini 6.5 Grendel?

[txgunner00]

So, jt distributing would be a good upper to start with?

Generally any forged upper or lower from a quality manufacturer is good to go. There are only a handful of forges that provide the banks from which all receivers are made. The difference is in the machining and finish. I would shy away from cast or extruded receivers. I'm sure some folks have had good luck with them but forged or billet receivers are pretty much guaranteed performers.