I've put a couple hundred rounds through the Gen4 G21 rental at my local range - I'm sure this thing has had thousands of rounds through it with minimal mx and cleaning. All reloads. The only BTF came from brass bouncing off the lane dividers. I set the plastic tote they give you to carry your rental to my right against the lane divider (roughly to the gun's 4/5 o'clock) and probably 75-85% of my brass winds up in that tote. Seems to be pretty consistent. Happy enough with it that I'll be buying one. Good luck with yours. Wanna kill these ads? We can help!