FN SLP MK1 Police 12 Ga Shotgun | 22″ Barrel

Description

I remember the first time I ran a 3-Gun stage with a borrowed FN SLP. It was slick, fast, and ate every cheap, low-brass bulk pack shell I fed it without a hiccup. That reliability stuck with me. So, what is the FN SLP MK1 Self Loading Police 12 Ga, 22″ Barrel, 8rd? It’s a purpose-built, gas-operated tactical shotgun designed for high-volume, high-stress use. Think law enforcement, competitive shooting, or serious home defense. It’s not a hunting gun you’ll baby; it’s a tool you’ll run hard and trust to work. At $1127.06, it sits in a sweet spot between duty-grade reliability and competitive performance.

Here’s the thing—the SLP’s secret sauce is its dual-piston, self-regulating gas system. FN calls it the ‘Self-Regulating Gas System’ and it’s not just marketing fluff. I’ve put hundreds of rounds through this platform, mixing light 2¾” target loads with heavy 3″ magnum slugs in the same magazine tube. The system automatically adjusts the gas pressure, ensuring reliable cycling across a huge spectrum of ammunition. That’s a massive advantage when you can’t predict what you’ll need to feed it next. The 22″ barrel gives you a great balance between maneuverability and sight radius, and the 8+1 capacity (with the included extended magazine tube) means you’re not reloading every five seconds.

The build quality is exactly what you’d expect from FN Herstal. The receiver is machined steel, the controls are robust, and the overall fit is tight. It feels substantial in the hands—this is a 7.9 lb shotgun, so you know you’re holding something solid. That weight, combined with the gas operation, soaks up a ton of recoil. Follow-up shots are noticeably faster and more controlled compared to many inertia-driven or pump-action guns. The stock is a classic polymer design with a decent recoil pad, and the forend provides a solid, textured grip. It’s a no-frills, functional layout that works.

FN SLP MK1 Specifications

Specification	Detail
Gauge	12 Gauge (3″ Chamber)
Barrel Length	22 Inches
Overall Length	42.5 Inches
Weight (Unloaded)	7.9 lbs
Magazine Capacity	8+1 Rounds
Action	Gas-Operated Semi-Auto
Choke	Fixed Cylinder Bore (Improved Cylinder on some models)

Let’s talk pros and cons. The biggest pro is that legendary FN reliability. This gun runs. The dual-piston system is brilliant for mixed ammo. The 8-round capacity is a real tactical benefit, and the overall design is simple and proven. It’s also incredibly easy to maintain. The cons? It’s not the lightest shotgun out there. Some might find the fixed choke limiting for specialized uses, though for its intended roles, it’s perfect. The price is an investment, but you’re paying for a pedigree of performance that’s been proven on ranges and in duty holsters worldwide. This unit is drop-in ready for your next match or duty rotation—no gunsmithing required to get it running right.

So who is this for? Primarily, it’s for the shooter who needs uncompromising reliability. That includes competitive shooters in 3-Gun or tactical shotgun matches who can’t afford malfunctions. It’s for law enforcement officers or armed professionals seeking a duty-ready semi-auto. And it’s for the serious civilian defender who wants a top-tier, no-excuse tool for the home. If you’re just looking for a cheap plinker, this isn’t it. But if you need a shotgun that will perform under pressure, this is a top contender.

Frequently Asked Questions

Q: Will it cycle light target loads reliably?

A: Absolutely. The self-regulating gas system is designed specifically for that. I’ve run 1-1/8 oz, 1145 fps promotional loads without a single failure. It handles the full range from light target to heavy slugs.

Q: Is the magazine tube easily removable for cleaning?

A: Yes, it threads out from the front of the receiver. Disassembly for a thorough cleaning is straightforward and doesn’t require any special tools, which is a big plus for maintenance.

Q: What optics or accessory mounting options does it have?

A: The MK1 model features a Picatinny rail section machined directly into the top of the receiver. This provides a solid, stable platform for mounting red dot sights like the Aimpoint Micro series or Trijicon RMR. The forend also has slots for M-LOK compatible accessories.

If the idea of a gas-operated, high-capacity tactical shotgun from a maker with FN’s pedigree speaks to you, this SLP MK1 is worth a close look. It’s available at firearms-missouri.com for Missouri residents and nationwide. Check the full listing for current availability.