.... as a plebe / freshman at military college we had to keep them locked up in the armory. As upper class men we could keep them in our barracks room under an honor system that they would be kept unloaded and locked up in a foot locker.
Sometimes about 10 to 15 of us would go on a Sunday to the city dump to plink at rats, safely, in a line abreast, .... 22's, 45's, shotguns, etc. No one ever got in trouble for mis-handling, accidental discharge, etc. One guy even had a replica muzzle loader canon we would shoot on occasion... although the rats were at a distinct advantage in hiding from that big boomer.
When I transferred to a civilian college across town, I still kept guns in a foot locker in my dorm room and later when sharing an apartment in an old house. Never even questioned as to if it was allowed or not.
In thinking about it, if we ever would have heard a shooter was on campus, I'm confident he / she would have been taken down well before the campus rent-a-cops or city police would have arrived. This was in an era when most young men and women were taught by the parent (s) gun safety, shooting skills, etc .... starting with BB guns when in grade school.
Having a permitted gun in a dorm might help against a dorm shooter, or in a vehicle to use against a campus shooter, ... but not likely helpful when the shooter is in a classroom building. I don't think it would be good to allow guns in class rooms in todays world .... particularly for a conservative student having to pay tuition to listen to the ultra lib professors spewing their leftist ideals.