50 Armscor 180gr FMJ rounds being sent downrange at Indy Arms Co yesterday morning.
Ballistically, these are about what I'd choose if I were to be running up the round count in a class with this gun; they've got enough oomph to cycle the thing reliably, even with the heavier recoil spring, but they're not so fatiguing that you couldn't shoot a few hundred in a day without risking carpal tunnel syndrome. The big Glocks do serve as pretty decent recoil sponges.
This makes 730 rounds since the Glock 20 was cleaned or lubricated, with two failures to feed (#401, #454) and one failure to fire (#598). 1270 rounds to go.