So what’s the big deal with short-barreled rifles and shotguns? I don’t see how they’re inherently more dangerous to the user.
Nothing to do with personal safety of the user/carryer: Usually un-mentioned in discussions of short-barreled is the parallel requirement that long guns have an overall length at least 26”. At the time the rule was written the M1 Carbine Paratrooper was the standard for a small rifle IE 16” barrel and 26” overall with the stock folded. The issue/concern right or wrong is concealability. Anything shorter than 26” needs to be dressed like a handgun. No folding/detachable shoulder stocks and no scattergun ( shotgun) bores. Until recent times it was always about gummint income, not safety or bans, the rules created tax income for those guns falling outside the rules-——no more—no less.