A month or so ago I bought a Mossberg 930JM (Jerry Miculek). It's a Mossy 930 that comes set up for 3-gun competition out of the box. It's got an enlarged bolt release button, the receiver is flared slightly around the loading port, and it comes with Nordic Components mag tube extensions. This is nice since it makes it very easy to add mag capacity.The gun is advertised as either 8+1 or 9+1. I bought the 8+1, which is really an 8 and a half +1. I added an "extra large" Nordic 3/4" cap and I can just squeeze 9 in the tube using 2 3/4" loads. They make a longer 1.5" cap, which would allow easier loading of 9+1, or that same tight fit of 3" shells. It also comes with a full set of chokes, a choke wrench, and chamber flag.
I bought it at the BX for cheap, since I don't think most of the customers knew what to make of a Mossberg without a ridiculous muzzle device or a chainsaw grip. But I was going TDY for a month the next day, so I just got to shoot it this weekend.
I really like it. The shotgun stage had 3 slug shots at about 75 yards, and then a course of stationary clays and steel at 15-25yds. I didn't win, but for the first time out with the gun, I did ok.
Loading weak hand was much easier than on my 1100. The loading gate didn't bite my thumb, but it does in dry practice, so I might get it welded up in the future. The fiber-optic front sight was dead on for the slug shots, though you really have to get down on the stock to line up on the sights. The gun comes with a ton of inserts to change LOP and maybe stock angle. I don't really know how to use them, and I'd rather just practice and learn the gun as-is.
I threw almost all the slugs high when I ran the stage, so after everyone was done I expended the remaining 6 slugs I had on figuring out where it was hitting. That's when I figured out I need to really hunker down on the gun to see no rib and just sight and it hits perfectly. I nailed the plate at 75yd 5/6 shots.
The slugs left my shoulder a little sore the next day, but, at the time, the gun tamed them nicely. 7 1/2 federal game loads were pussy cats.
Many have written great reviews on the 930 series, typically the SPX. I don't think this gun loses anything against the other variants, depending on your sight preference, but if you're shooting 3-gun, this one is the way to go.