On switch barrel (if that is what there called) shotguns, and more specifically the 870, do you modify it in any way when you put the slug barrel on. Although the accuracy is fairly decent, do you do something to try and squeeze a bit better results from it. Reading on Shotgun world they tried the "pop can shim" to tighten up the movement of the barrel. Has anyone tried this or any other method that you feel works better.


















































