The Mossberg 500 series of shotguns is one of the best pump-action shotguns available. While I have always liked the Remington 870 for a pump 12 gauge, I would not hesitate to use or carry the Mossberg 500. You may want to look at the 590 though for duty use. The only thing that kept me from getting the 500 or 590 was the fact that my Dept's policy mandates the 870. A lot of guys prefer the safety on top of the Mossberg instead of Remington's button safety near the trigger.
This article on Wikipedia is pretty good: Mossberg 500 - Wikipedia, the free encyclopedia
The U.S. Marine Corps (and supposedly the Army, and the Navy) still use the Mossberg 500 in one form or another (They also use the Remington 870). Plenty of police departments issue, allow, and use the Mossberg 500/590. There are plenty of extras out there to tweak and/or otherwise customize the weapon to meet your needs. Buy and use the Mossberg with confidence.
This article on Wikipedia is pretty good: Mossberg 500 - Wikipedia, the free encyclopedia
The U.S. Marine Corps (and supposedly the Army, and the Navy) still use the Mossberg 500 in one form or another (They also use the Remington 870). Plenty of police departments issue, allow, and use the Mossberg 500/590. There are plenty of extras out there to tweak and/or otherwise customize the weapon to meet your needs. Buy and use the Mossberg with confidence.