Mossberg 590A1 Ghost Ring Sight 9-Shot – Magpul SGA Custom, 20" Heavy-Walled Barrel
Purpose-built for hard use and thoughtfully upgraded, this 12 ga Mossberg 590A1 blends military-grade durability with practical enhancements for the modern shooter. A Parkerized, heavy-walled 20" barrel pairs with an 8+1 magazine that sits nearly flush with the muzzle, while factory ghost-ring sights and a protected orange-blade front post provide fast, daylight-visible indexing. The previous owner installed a Magpul SGA stock and a barrel/magazine clamp that carries Picatinny segments, giving you a rock-solid recoil pad, spacer-adjustable 13" length of pull, integrated sling slots, and immediate light or laser mounting options. If you’ve been waiting for a true duty-grade pump that’s already set up for work, this is it.
Condition
Very good overall. The Parkerized metal shows scattered superficial scratches and handling marks but no abuse; edges remain sharp and the phosphate finish retains its deep, even tone. Polymer furniture is clean with only light rubs. The bore is excellent—mirror-bright with crisp lands and no pitting. Action cycles smoothly, safety and controls operate as designed.
What’s Included
• Mossberg 590A1 12 ga pump shotgun as pictured
• Magpul SGA stock (installed)
• Steel barrel/magazine clamp with left & right Picatinny rail sections
Built on Mossberg’s all-steel 590A1 receiver, this shotgun passed the U.S. military’s MIL-SPEC 3443G endurance trials, a pedigree shared with examples fielded by the Navy and Marine Corps. Dual action bars, an anti-jam elevator, and a clean-out magazine tube cap underscore its reliability. The heavy-walled barrel is bayonet-capable (M7/M9 pattern) and retains a fixed Cylinder bore—ideal for buckshot, slugs, and specialty loads alike. Chambered for both 2¾" and 3" shells, it offers flexibility whether you’re running reduced-recoil training rounds or full-power defensive ammunition.
The ambidextrous top-tang safety and metal trigger guard are intuitive and glove-friendly, while the receiver comes drilled and tapped should you prefer to add an optic or full-length rail. Extensive aftermarket support means you can tailor the gun further, but its current configuration is already mission-ready.
Whether you’re assembling a serious defensive toolkit, seeking a proven platform for duty or training, or adding a U.S. military-spec variant to your collection, this customized 590A1 offers rugged performance and thoughtful upgrades in one turnkey package. Give it a place in the rack and let it earn its keep.