I have an old Beretta a303 20 gauge and the barrel states 2 3/4" shells only, is it possible to have it opened up to shoot 3" shells? I really like the gun, but some areas I hunt are Steel Shot only and it is tough to find 20 gauge steel shot in the shot size I want in 2 3/4". I know I could ask a gunsmith, but I was curious if anyone here knew for certain or had done it.