Re: serial # ?
Measure the end of the barrel. 12 gauge is about 3/4 inch in diameter (.0,730). 20 is about 5/8 (0.620).
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.