I hunt at the Fort Knox military base for deer...they allow shotguns or muzzleloaders. I have killed deer with both on the base, but the 12-gauge Hornady 300 gr SST at 2000 ft/s is HOT.

Fort Knox limits hunters to 10 rounds for shotguns (buckshot not allowed)or 10 bullets with 100 grain charges for muzzleloaders.

They also expressly forbid the use of smokeless powder (e.g. H110) for use in muzzleloaders (i.e. Savage 110ML) which can produce some seriously hot ballistics.