I've been asked by a lot of our club members what constitutes a decent tactical shotgun for our Three-Gun matches or home defense. Essentially, any short-barreled, 12 gauge shotgun, capable of holding five rounds, that you would select as a home defense gun would work just fine with a few minor refinements.
ACTION TYPE: For cost effectiveness, weight consideration, and total reliability, I'd go with a name-brand Pump shotgun. Two come to mind right away. The Remington 870 and the Mossberg 500 or 590 series. Both are reliable and both come in a tactical model. They can also be found on the used gun rack at most gun shops.
From time to time, gun shops will have Remington 870 police trade-ins that they sell off cheap. These police trade-ins may have a few cosmetic blemishes on them but they are still solid shooters. I have purchased used Remington's and Mossberg Tactical shotguns from $125.00 to $250.00. The Mossberg is normally on the lower end of the price spectrum when found used.
WHICH MODEL: In my estimation, the Remington 870 is the King of all Pump shotguns! I've owned several, and have never had a reliability issue with them. I've also owned both the Mossberg 500 & 590 models with the same results. The Mossberg may be a bit more ambidextrous because the safety is located on the Tang of the shotgun, which is located right under the shooter's thumb. As a Lefty, I appreciate this a great deal. The Model 500, has an alloy receiver so if you're recoil sensitive, it will definitely bark a bit more than the 590. Personally, I shoot a Benelli M4 semi-auto tactical shotgun, but I'd buy either of the above two brands without hesitation.
ACCESSORIES: Now for the refinements I mentioned. Since we're always shooting in low, to no-light conditions, a tactical illuminator is almost a necessity for Three-gun matches. The Streamlight TLR-1 is an excellent light and can still be found for under $100.00. Also, the Streamlight Universal Light Mount, which clamps to the magazine tube of almost any 12 gauge shotgun, can be purchased for under $25.00 from several on-line sources. "LA Police Gear" being one of them. For more information got to: http://www.lapolicegear.com/
The other addition I'd install is a good tactical sling. The sling makes using the shotgun far more comfortable and will be very beneficial while you're reloading. The Sling-Systems model is hard to beat. For more information go to: http://www.slingsystem.com/
RECOIL FACTOR: Shotguns produce recoil; it's just the nature of the beast. With hotter loads, the felt recoil can become quite substantial. If you don't want to eat a bunch of recoil while you're supposedly having fun there are a few options open to you. The first is to shoot Reduced Recoil shells. Federal, Winchester, and Remington all make Reduced Recoil loads for law enforcement use. They are also available to the public. I prefer the Federal brand. The problem is finding them right now. The gun-buying frenzy that the new administration (Yes We Can) created has dried up a lot of dealer's inventories. My local ammo provider has been out of stock for well over a year.
The second option is to install a good recoil pad. The Pachmayr Decelerator pad, or the KICK-EEZ pads are tops, but having a quality pad installed can be just as expensive as a good replacement stock.
With that being said, the only other item I'd consider is a replacement rear adjustable stock with a pistol grip to help control recoil. The best one's I've found for this is the Knoxx Stock from Blackhawk. The "Spec-ops" stock has a recoil-reducing system built into it which supposedly absorbs about 95% of felt recoil from hot loads and the length of pull is adjustable up to 4". This will allow the shotgun to be far more manageable and will fit even the smallest statured shooters. See: http://www.blackhawk.com/
I have installed Knoxx stocks on both a Remington Model 870, and a Mossberg 500. While they work great, I'd argue their claim about 95% recoil reduction. It feels more like 50% to me.
SIGHTS: Most of these shotguns come with a standard Bead front sight and that's it. If you're lucky enough, you may come across one with rifled sights or the Ghost-ring type sights. If you're buying a shotgun new in the box, I'd probably order one with the Ghost-ring sights on it, if they are available. Ghost-ring sights resemble those sights found on a military rifle. They are adjustable for both windage and elevation (left/right & up/down). These sights will make the shotgun more rifle-like.
ELECTRONIC SIGHTS: Even though we also allow the use of electronic optics such as the Eo-Tech, Ultra-Dot and Aimpoint, they are not necessary or required for Three-gun. Your scores will of course improve by using an electronic sight, but they are not mandatory. If you ever attend a tactical shotgun class and your shotgun is so equipped, remove the dot sight before going to the class. The weight will become a major issue when you're shooting several hundred rounds in one day. For Shotgun training course information go to: www.teamspartan.com
AMMUNITION: We shoot twenty (20) rounds of 12 gauge Shotgun ammunition for record. Ten of these rounds are 00-Buckshot (9-pellet variety) and ten rounds are Rifled Slugs. The 00-Buck is fired at fifteen yards in two strings of five rounds, fifteen seconds per string. The Rifled Slugs are fired at twenty-five yards, in two strings of five rounds, fifteen seconds per string.
One word of advice. If you're going to use a shotgun as a home defense firearm I'd load it with Trap loads (7 1/2 shot), especially if you live in an apartment. 00-Buck and Rifled Slugs will tear right through and inner and outer wall like nobody's business. You run the risk of injuring an innocent bystander by using heavy loads in a home environment. Trap loads are devistating at close range and even out to 50+ yards.
I hope this information has been of some use to those of you who may be thinking of buying a tactical shotgun for home defense, or for shooting Three-gun.