I'm still new with muzzleloaders and have never hunted, but in Massachusetts, is a muzzleloader not a rifle? Or do they mean center fire cartridges?
I think the definitions vary based on useage. I have seen muzzleloaders referred to firearms and rifles in some contexts. For Massachusetts hunting, a muzzleloader does not fall under the definition of a rifle and therefore can be used to hunt deer. I was not trying to be technical but my understanding is this:
For hunting many states , (such as Massachusetts), the hunting rules don't consider muzzleloaders or shotguns as rifles. Shotguns can be smooth bore, or have a rifled barrel, but are still referred to as shotguns for that definition and most peoples definition. A shotgun for ATF purposes is considered a firearm requiring a gun license.
Rifles, as far as I know, always have a rifled barrel and can shoot centerfire or rimfire cartridges. A conventional rifle for ATF purposes is considered a firearm requiring a gun license.
Muzzleloaders, can be rifled or smooth bore, are generally also legal to hunt deer with in Massachusetts. They are not considered rifles (MASS does not allow deer hunting with a rifle). Also, muzzleloaders are not considered a firearm according to ATF definitions of a firearm, so they may purchased by anyone of legal age, whether or not they have a firearms license. The ATF, as far as I know, distinguishes A MUZZLELOADER FROM A FIREARM because it doesn't use cartridges which contain the powder, bullet and primer (called bullets by laypeople), but bullets are simply the projectile part of the cartridge. A muzzleloader had those items loaded separately, down the shooting end of the barrel vs the breach. Some states allow breach loaded muzzleloaders and consider them muzzleloaders for hunting purposes, and many states don't.
If I am off on this anyone out there feel free to chime in. no offense taken.