The cartridge is .50BMG shot in a bolt gun. The load is WC860 powder, 210 gr. with M33 ball bullet, 650gr. Only variation was the headspace distance between the rounds. Range from -.001 to -.004 on the gauge. All the brass was trimmed to 3.900 and seated at 5.435.
If you heard the bang,
You weren't the target.