^^This is good advice.
As far as "930's don't run," that hasn't been my experience.
I bought a 930JM pro about a year ago and have had only two issues with it. Initially the juncture between the magazine tube and nordic extension was a little rough and would catch the follower, but about 10 minutes of light polishing fixed that problem for good. Also, after about 400 rounds the pivot pin for the shell stop broke, causing the gun to stop feeding shells from the magazine tube. Mossberg sent me a replacement pin plus a few extra for my spares bin no questions asked. I haven't had any issues with the shell stop since.
I have replaced the stock lifter with a welded and polished lifter from CJ SMith at Sky Tac, and am gradually working through all of the performance tweaks that are recommended for 930s (including adding some of the performance parts from one of those companies in Oregon!). I am happy with the shotgun, especially considering how inexpensive it has been thus far. As long as I keep it clean it runs like a top.
Can't speak to the Stoeger but I've read they may have some quirks of their own, and they do require some additional parts to be "3-gun" ready when compared to the 930.
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