I own several shotguns and was recently given a Mossberg 500 with a 28" barrel. I was considering cutting 8" off the barrel and using it as my HD gun (along w/ my .357). What considerations do I have to keep in mind when chopping the barrel? Any help would be appreciated. Also, the minimum length in my state is 18". Should I cut it down to 18" or 20" like I had planned. Thanks.