If it is a bolt action shotgun, it is probably a Mossberg. Somewhere on the gun should be a model number. Normally something like 101.0134, or something similar. You can check it against this cross-reference list.
Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297
I always take precautions.
Beware the Evil Bullet Fairies.