I have an old 870 and recently purchased a new 20" smooth bore barrel for it. As I installed it I felt a lot of resistance when the barrel extension contacted the barrel support. I had to use a rubber mallet to seat the barrel and in order to remove the barrel I needed to use the foregrip as a sort of slap hammer to drive the barrel off. My question is, given the fact that the barrel does seat completely without any play, is the gun safe to fire. I will be calling Remington in the morning and consulting with a local gunsmith as well but I thought I'd post the question here also.