500rd case of Remington UMC 10mm 180gr FMJ. For some reason I had mentally filed the Remington 10mm range load in my mind as basically being .40 S&W power levels in a longer case.
The sturm und drang that accompanied each shot was definitely not .40 S&W-level. There was the typical Remington fireball one associates with their hotter handgun loads, and it flung the ejected brass with vigor. I checked their website and it claims 1150fps at the muzzle. I'll need to chrono it as soon as I get some good weather, probably tomorrow morning, but I'll be kinda surprised if it doesn't come darn close to the claimed velocity.
This makes 1130 rounds since the Glock 20 was cleaned or lubricated, with two failures to feed (#401, #454) and three failures to fire (#598, #1,016, #1,029). 870 rounds to go.