"I think they epoxy a wooden dowel inside to limit it to 5 rounds."
Just a quick question, can you replace the original stock for a Magpul shotgun stock?
No. Absolutely not.
The 930 action goes right through the stock, similar to an AR-15.
Stock options are limited on the 930. A popular one that can be used is the Mesa Tactical Urbino stock.
Can you bring in some more mossberg 940s?
ie.
the Mossberg 940 PRO Waterfowl Semi-Auto12 Ga 28″ Barrel 85151
or
Mossberg 940 Pro Turkey 12ga 3" Semi Auto Shotgun 24" Barrel, 4+1 Tube, Mossy Oak Greenleaf
or
Mossberg 940 Pro Field 12 Gauge