Thanks Payne, always enjoy shooting with you, you're a great shooter and ambassador to our sport.
Well I truly believe I have found the culprit. I spent some time researching my issue and thanks to great folks at shotgunworld.com and mossberg owners forum I learned a ton about the platform. The heart of the system, and part that needs the most attention, is the actual piston itself. The malfunction I had was the fired round would eject, new round would feed, the bolt would go forward, but the slide (the bottom part of the bolt assembly) would not go into battery and not lock up. What I learned that this malfunction is text book when the piston drags. When the piston drags it prevents the slide from locking forward and locking up.
I learned two things, one I had to adjust my piston spring, and two I had to remove the gas piston rings and clean the rings and under the rings on the piston. Cleaning the exterior of the piston alone was not good enough. Once I adjusted (centered is really a better term) the spring, which is in the barrel forward of the where the piston resides, the barrel went on much easier. If you feel friction when installing or removing the barrel, or find marks on the mag tube, your piston spring probably needs to be adjusted and centered. To adjust the piston spring, I used a deep well socket, 19mm, or you can use a dowel rod close to the same size as the mag tube. With the dowel/socket/rod, then use that to center the spring, you may see that it is not centered and one edge is exposed more then the other, not the circle within a circle so to speak. Again, once this was adjusted I was very impressed with the difference it made on the reduction of friction on the barrel.
Then once I removed the two piston rings I found a lot of hard, baked on crud. I put all of the individual pieces in my cleaner. This worked somewhat but I still needed to scrape, pick, and brush off the parts. Once clean, I reassembled everything except of the fore arm. Here is where I really saw the difference. The piston should move pretty easily when everything is assembled and you pull down on the spacer. Likewise the piston should install and remove very easily. Mine was always very tight to install and remove and did not move easily on the mag tube. Now that it's clean it installs/removes very easily, practically falls out, and moves on the mag tube. It was also recommended to polish and smooth up the mag tube but aside from a good cleaning I have not polished that yet.
Judging by just how the gun feels on the bench I think I have found the issue was some needed adjustment and maintainence. I can't really blame the gun for that as I have put alot of flawless rounds through it previously. I am going to get to the range with a variety of ammunition from high brass high DRAM to the cheap stuff and test it out.
I can post some photos or maybe a video if anyone is interested, I'd be happy to share what I've learned so far. If this is it, I am still very impressed with this shotgun for the price. If the piston just needs some TLC a little more then I expected I am still perfectly ok with that and when it runs, it runs and shoots great for me.