Since I already have three upgraded Mossberg 500's (metal trigger groups and metal tang safety levers) identically kitted up in "combat" configuration and don't feel the need to invest in any 590 goodness, I thought it through a little bit and decided to do a little work on one of mine to see if I could kit one up to mount a bayonet on it without it looking like a crappy bolt-on "afterthought" contraption. I selected the one on the far right that has the newer style barrel nut that is a wee bit thicker than the two older style ones to the left. I took out the barrel nut and turned the front portion of it down in my drill press using (sacrificing actually) a flat mill (aka bastard) file to the proper diameter of the bayonet's barrel mount, while leaving enough of the knurling so you can still twist it off by hand without tools. This is the ONLY permanent modification in the entire project, and if you screw it up you can get a new one online for cheap... low risk operation. I was going to completely fab the rear mounting lug from all the sheite I have in my scrap brick-a-brak stuff behind my workshop, but I found the perfectly configured "doo-dad" online for $20 that solved the mag-tube mounting method, front sling mount point, and "sleeknes" concerns I was wrestling with. The bonus was it has two small very low-profile pic-rails (one on either side) to mount a light to if I want, yet not be a snag point should I leave them empty... BRILLIANT! With a dab of blue loctite on the bolts/screws of the rear lug, the whole thing is rock-frikin'-solid and looks as close to "factory purposed" as a garage malcontent and his M500 can get, as well as still be field stripped w/o tools. Just try and wrestle this pig out of someone's hands now!!