Description
The Mossberg 500 JIC Mariner 12 Gauge 18.5 in Pistol Grip is a purpose-built defensive shotgun designed to thrive in marine, coastal, and high-humidity environments. Its corrosion-resistant Marinecote finish and compact 18.5-inch barrel make it a reliable choice for boaters, campers, and home defenders who need a rugged pump-action that won’t rust or fail when conditions get wet. The package includes an orange water-resistant carrying tube, shoulder strap, multi-tool, and serrated lock-back knife, making it a complete ready-to-stow kit.
Per Mossberg specs, this model ships with a fixed cylinder-bore choke tube and accepts both 2¾-inch and 3-inch shells, giving you flexibility in ammunition selection for defense or utility use. The black synthetic pistol grip stock provides a secure hold even with wet hands, and the overall length remains compact for easy storage in a boat locker, truck cab, or closet. Last updated: April 2026.
| Manufacturer | Mossberg |
|---|---|
| Model | 500 JIC Mariner 12 Gauge 18.5 in Pistol Grip |
| Material | Marinecote-treated aluminum receiver, synthetic stock and forearm (per manufacturer specs) |
| Compatibility | 12 gauge 2¾-inch and 3-inch shells, fixed cylinder-bore choke |
| Finish | Marinecote silver corrosion-resistant coating |
| Weight | 5.5 lbs (unloaded, per manufacturer specs) |
| Condition | New |
Key Features
- Marinecote Corrosion-Resistant Finish – WHY IT MATTERS: This coating protects the receiver and barrel from saltwater, moisture, and humidity, so you can store the shotgun in a boat or damp environment without worrying about rust forming on critical components.
- Compact 18.5-Inch Barrel with Cylinder Bore – WHY IT MATTERS: The shorter barrel keeps the overall length manageable for tight spaces like a vehicle, boat cabin, or home hallway, while the cylinder bore delivers a wide shot pattern ideal for close-quarters defense.
- Pistol Grip Stock for Secure Handling – WHY IT MATTERS: The synthetic pistol grip gives you a firm, one-handed hold when moving through wet or unstable environments, and it reduces the chance of the gun slipping from your grasp during rapid cycling.
- Complete JIC Kit with Carrying Tube – WHY IT MATTERS: The orange water-resistant tube keeps the shotgun, multi-tool, and knife protected and organized, so you can grab the whole kit and go—perfect for emergency bags or marine storage.
- Accepts Up to 3-Inch Shells – WHY IT MATTERS: You can run standard 2¾-inch target loads for practice or switch to 3-inch magnum buckshot for maximum stopping power, giving you versatility in one platform.
Who It’s For
This shotgun is built for shooters who need a dependable tool in wet or corrosive environments—boat owners, coastal property residents, and anyone who stores a firearm in a humid garage or truck. It’s also a great choice for new defensive shooters who want a simple, low-maintenance pump-action that’s easy to operate under stress. Families teaching teenagers or young adults about firearm safety will appreciate the manual of arms and the included kit for secure storage.
Pros and Cons
- Pro: Marinecote finish resists rust far better than standard blued or parkerized shotguns, extending service life in salt air.
- Pro: The JIC kit includes a knife and multi-tool, adding value beyond the shotgun itself—great for emergency preparedness.
- Con: The fixed cylinder-bore choke limits pattern tightness at longer ranges; you won’t get the same reach as a shotgun with interchangeable chokes for hunting.
How It Compares
| Feature | Mossberg 500 JIC Mariner | Remington 870 Marine Magnum | Maverick 88 Security |
|---|---|---|---|
| Finish | Marinecote (silver) | Electroless nickel | Blued |
| Barrel Length | 18.5 in | 18 in | 18.5 in |
| Stock | Pistol grip synthetic | Full synthetic stock | Full synthetic stock |
| Capacity | 5+1 (2¾-inch shells) | 4+1 (2¾-inch shells) | 5+1 (2¾-inch shells) |
| Included Accessories | Carrying tube, multi-tool, knife | None | None |
| Price | $668.65 | ~$650 | ~$250 |
The 870 Marine Magnum offers a similar corrosion-resistant finish but lacks the pistol grip and JIC kit. The Maverick 88 is more budget-friendly but has a standard blued finish that requires more care in wet conditions. For marine use, the Mossberg 500 JIC Mariner delivers the best all-in-one package.
Frequently Asked Questions
What is the capacity of the Mossberg 500 JIC Mariner?
It holds 5 rounds in the magazine tube plus 1 in the chamber when using 2¾-inch shells. With 3-inch shells, capacity drops to 4+1.
Can I change the choke on this shotgun?
The barrel comes with a fixed cylinder-bore choke and is not threaded for interchangeable chokes. You would need to replace the barrel to use different choke patterns.
Is the carrying tube included in the price?
Yes, the orange water-resistant tube, shoulder strap, multi-tool, and serrated lock-back knife are all included at the listed price.
Does the pistol grip make it harder to shoot accurately?
A pistol grip changes the point of aim and requires practice, but many shooters find it easier to control in close-quarters defensive situations. It is not ideal for clay shooting or long-range patterns.
Buy with Confidence
- ✅ Nationwide delivery to all 50 states
- ✅ Ships within 1-2 business days
- ✅ 30-day return policy
- ✅ Secure checkout with encryption
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