I’ve been researching for future builds and the reading I’ve done is that Aero Precision makes them for PSA, they also make the COP upper for Armalite, and it appears to be the same for Spikes Tactical. I don’t know for a fact but that’s what I’ve been able to gather. I’m planning on building one, driving the crap out of it and see how it holds up, I ain’t scared:D Well it helps when you already have a Colt, I went spendy now I’m going cheap:)
Reread OP has two Double Star Lowers, my bad I misunderstood:)
My two PSA lowers were made by LW Schnieder. I know some came from Aero Precision.
+1
My PSA mid-length has about 500 rounds through it and not a single issue.
I know, I know, 500 rounds ain’t dink, this is a fresh out of the box complete rifle. Rounds were shot over a 2 week period and I’ve done nothing to the gun other than load it and pull the trigger.
The jury is still out on long term durability, but so far I am very happy customer. For the money this is a great gun, IMHO it would be a great gun for more money 