The reciever is unique to the 12ga size, the 16's and 20's are built on their own frame. Post 855,000 are straight cut, with dimensional interchangeability from gun to gun. Pre 855,000 the 'interupted threads' that allow the barrel to come off, actually had a pitch to them. I do know where there are some pristine ones if someone took a pliers to yours in the past.ĭO NOT try to put a new(er) barrel into your reciever, it will ruin it. The style of barrel nut you have is hard to come by. The magazine nut turns to the right to loosen. The barrel is serial nbr'ed to the reciever, often times/mostly with a -2 -4 etc indicating the choke, along with Full, Mod ImpC etc. If you look at the front flat of the reciever, next to the barrel, you will see the matching serial nbr. Prior to that, they were individually fitted to each reciever. The barrels on Ithacas became interchangeable after serial nbr 855,000. Well worth hanging on to.ĭid you measure that 29 1/2 from the front of the reciever ? if so, then that is a 30' barrel (measured overall). What you have is a nice old, late 40's Ithaca 37 12ga. here is a link to serial nbrs by dates on the Ithacagun website
