Mossberg 56436 500 All Purpose Full Size 20 Gauge Pump 3″ 5+1 26″ Matte Blued Vent Rib Barrel, Matte Blued Integral Scope Mount Steel Receiver, Fixed Black Synthetic Stock, Right Hand, Accu-Set Chokes
Video review
Expert review
About this product
What is the Mossberg 56436 500 All Purpose Full Size 20 Gauge pump shotgun? It's a 5+1 capacity, 3-inch chamber pump-action scattergun built on Mossberg's military-proven 500 series steel receiver with an integral scope mount and Accu-Set choke system for versatile patterning control. This model delivers the dual extractors, twin action bars, and positive steel-to-steel lockup that made the 500 platform a global standard for reliability across law enforcement, military, and civilian hands. At $408.99, it represents a purpose-built entry point into a battle-hardened system that's often misunderstood as merely a hunting tool.
What is the Mossberg 56436 used for?
The Mossberg 56436 is primarily a versatile field and utility shotgun for small game hunting, pest control, and home defense training with reduced-recoil 20-gauge loads. Its 26-inch vent-rib barrel and Accu-Set choke system allow for patterning from improved cylinder to modified constrictions, making it effective on squirrels, rabbits, and upland birds within 40 yards. The integral scope mount receiver accepts Weaver or Picatinny bases for low-power optics, which is uncommon on a field gun at this price, while the 5+1 capacity meets or exceeds most state hunting regulations for migratory birds.
How does the Mossberg 56436 compare to the Stevens 555 Sporting O/U 20 Gauge?
The Mossberg 56436 is better for rugged reliability and tactical adaptability, while the Stevens 555 Sporting 20 Gauge O/U review is superior for refined, fast handling in competitive clay sports. The Mossberg's 5+1 tubular magazine gives it a 67% higher on-board capacity than the over-under's two-round limit, and its steel receiver is rated for tens of thousands of high-pressure 3-inch shells where aluminum receivers fatigue. However, the Stevens breaks down to 42 inches for transport versus the Mossberg's fixed 46.5-inch overall length, and its walnut stock offers traditional aesthetics the black synthetic lacks.
What does it weigh and what are the dimensions?
The Mossberg 56436 weighs 6.75 pounds (108 ounces) unloaded and measures 46.5 inches in overall length with its 26-inch barrel. The receiver width is 1.6 inches at the ejection port, which is critical for scope mount clearance, and the length of pull from the trigger to the butt pad is 14.25 inches—a standard fit for most adult shooters. The ventilated rib is 8mm wide with a single brass bead front sight, and the 3-inch chamber adds roughly 0.75 inches to the forcing cone compared to a 2.75-inch-only chamber.
Who is this NOT for?
This shotgun is not for competitive clay shooters who need instant barrel selection or shooters who require a compact truck gun under 40 inches overall. The fixed synthetic stock and 26-inch barrel make it a poor choice for tight vehicle or blind use compared to the Stevens 555 Sporting Compact 20ga, which is 7 inches shorter. The 20-gauge chambering also means it cannot fire the heavier 12-gauge payloads preferred for waterfowl or turkey hunting at extended ranges beyond 50 yards, limiting its utility as a dedicated waterfowl gun.
What's in the box?
The factory box includes the assembled shotgun, one Accu-Set modified choke tube installed, two additional Accu-Set choke tubes (improved cylinder and full), a choke tube wrench, and the owner's manual with ATF compliance paperwork. Unlike some competitors, Mossberg does not include a hard case or trigger lock at this price point—you're paying for the steel and machining. The Accu-Set system uses a simple ball-detent and notch system rather than threads, which speeds field changes but requires keeping the wrench and tubes organized in a separate pouch.
Is the Mossberg 56436 worth it at $408.99?
At $408.99, the Mossberg 56436 is worth it for shooters who need a single, bombproof shotgun capable of handling everything from dove fields to security drills without modification. You're buying into a platform with 50 years of parts commonality and aftermarket support, where a $150 used 500 receiver can cost more than this complete gun. The steel receiver and integral mount alone justify the $90 premium over comparable aluminum-receiver pumps, as they allow mounting a red dot for low-light work without worrying about receiver flex under sustained fire.
Specs at a glance
Pros & cons
What works
- Steel receiver with integral scope mount — handles optics without flex, unlike aluminum receivers
- 5+1 capacity with 3-inch chamber — holds 67% more than a standard over-under shotgun
- Weighs 6.75 lb — 1.2 lb lighter than a comparable 12-gauge 500 model for all-day carry
- Accu-Set choke system — tool-less changes in under 10 seconds with three constrictions included
Trade-offs
- Fixed 14.25-inch LOP stock — not adjustable for shorter-armed shooters without aftermarket replacement
- No included case or lock — adds $40-60 for proper transport and storage
- Matte blued finish shows holster wear faster than parkerized or Cerakote finishes
- Top safety is ambidextrous but requires breaking grip to engage — slower than tang safeties
Key attributes
| upc | 015813564366 |
| manufacturer | Mossberg |
| manufacturer part number | 56436 |
| action | Pump Action |
| barrel finish | Matte Blued |
| barrel length | 26" |
| caliber/gauge | 20 Gauge |
| capacity | 5 + 1 |
| chokes included | Full/Improved Cylinder/Modified |
| color | Black |
| length | 36.7000 |
| safety | Tang |
| shipping weight | 8.3 |
| sights | Dual Bead |
Frequently asked questions
- Is it compatible with Mossberg 500 12-gauge barrels?
- No, the 20-gauge receiver will not accept 12-gauge barrels due to different magazine tube diameters and locking lug spacing. However, it is compatible with any Mossberg 500-series 20-gauge barrel with a 3-inch chamber and Accu-Set choke system, which are available in lengths from 18.5 to 28 inches from Mossberg's factory or aftermarket vendors like Carlson's Choke Tubes.
- Does it fit in a standard 48-inch rifle case?
- Yes, with 1.5 inches to spare. The shotgun's 46.5-inch overall length allows it to fit diagonally in most 48-inch Plano or Pelican hard cases with room for chokes and a box of shells. For air travel, I recommend removing the barrel, which reduces the package to 34 inches and fits TSA-approved locked cases under 50 linear inches.
- How long does shipping take to an FFL?
- Ironclad Armory processes orders within 2 business days and ships via UPS Ground, with transit times of 3-7 business days depending on your FFL's location relative to our Nevada warehouse. We require a copy of your FFL's license on file before releasing the shipment, which adds 24-48 hours to the initial processing window.
- Can I return it if it doesn't fit?
- No, federal law prohibits the return of firearms to non-licensees once they have been transferred through an FFL. If the firearm has a mechanical defect, we will arrange a warranty repair directly with Mossberg, which typically takes 14-21 days for evaluation and parts replacement. We strongly recommend handling a similar model at a local dealer before purchasing to confirm fit.
- Does this work with a Magpul SGA stock?
- Yes, the Mossberg 500 20-gauge is compatible with the Magpul SGA stock (model 700), which reduces length of pull to 12.5 inches and adds modular cheek risers. Installation requires a standard 3/8-inch hex key and takes about 15 minutes, but you'll lose the factory fixed stock's internal storage compartment for choke tubes.