I just got a used 590a1 from RJ's . I have a sling, sling mounts , red mount coming from gg&g . I have a Primary Arms SLX-RS10 red dot on hand . What are some hack/mods I can do to help run it better ? I have a small hang-up at the mag mouth, and the rims hangs up at time , can I radius the opening a little ? Will a Dead Mule recoil reducer help any as am turning 63 and does not take recoil like I use to .