Here are 3 clips of Darrell's brake on Ernie's 7mm Dakota (magnum cartridge) XP-100 handgun. This is a stout load for a handgun, even if it weighs about 11 (?) pounds.
These video clips are Darrell's new Radial Brake (not the Quick Discharge). I do not believe the new brake is on his web page yet.
here is both brakes: