Most agencies use the 870 for a simple reason, just like that little pink drum beating bunny, they keep going and going and going...
The much tweaked/shot Wingmaster here that is my HD insurance policy started out as one of the first. Pop bought it used around 1956, and I've personally put at least 3000 rounds throught it. There's three other 870s here, one started out at the Md Pen as a tower gun,
another in an Arlington Va, cruiser.
The prison I retired from had an 870 used for training from 1981 to 1998, firing hundreds if not thousands of rounds each year.Total repairs consisted of new wood.
While there's not much wrong with the
Mossberg, get the 870 Remington. Your great grandchildren will thank you for it...