re: Have a question for ya'll on a class 3 weapon

Short answer is no, not exactly.

With NFA they can not search without a warrant. ATF can request registration paperwork, that is the Form 1, 2, 3, 4, 5 or whatever else might have been used to register the weapon. See 26 USC sec. 5841(e). Depending on who you ask the ATF can request to inspect the weapon but I've never heard of that happening. They should need a warrant to ask a non FFL holder to show them a weapon.

If you have an 01 FFL, yes they can do an inspection on inventory and records once a year without any cause but only during the business hours listed on your FFL. 03 FFL they can inspect your log book but they have to make an appointment and it can be done at the ATF office.