purchased the SW3B M9 style bayonet specifically for use on my Mossberg 590A1 Retrograde. Can’t have a shotgun with a bayonet lug and no bayonet handy am I right? It fits the shotgun well, not perfect, but well. With just a little bit of effort, and I mean very little, it fits perfectly. The only criticism that I have so far is the wire bender/cutter feature. The post that serves as the pivot point for the blade is not tall enough to accommodate the thickness of the blade. This makes it impossible, at least on mine, to use the wire cutting/bending feature without some material modifications. This is not a major issue for me, just some feedback. All in all, a very good value. The blade is good, the handle and lug connector are very very solid. I will definitely purchase again if I have the need.