On the rifle range it is my EDM Windrunner in 50BMG. The original 'wasp nest' brake managed to amplify both muzzle blast and recoil. It wears a very effective clam shell brake these days, but you don't want to be in line with the ports when it fires.
On the pistol range it would be my repro Harper's Ferry .58 flintlock with 70gr FFg under a patched ball. Fun to shoot, but not to clean.
"Of all the things I've lost, I miss my mind the most." A. Brilliant