Description
The Rock Island VRBP-100 12 Gauge Bullpup Shotgun 20″ 5+1 is a magazine-fed semi-automatic built for compact handling and utility. Chambered for 12 gauge shells with a 20-inch contoured barrel, it shortens overall length by placing the action rearward while keeping usable barrel length. The design includes a black anodized receiver, polymer bullpup stock, integrated Picatinny rail, and flip-up sights for straightforward optic or iron-sight use. It ships with MobilChoke options to tailor shot patterns.
| Manufacturer | Rock Island Armory |
|---|---|
| Model | VRBP-100 (VRBP100A) |
| Material | Black anodized receiver, polymer bullpup stock |
| Compatibility | 12 gauge 2.75″ and 3″ shells (per manufacturer specs) |
| Finish | Black anodized |
| Weight | Approximately 8.2 lbs (per manufacturer specs) |
| Condition | New |
Key Features
- Bullpup Design — Why it matters: Shortens overall length to about 30 inches while keeping a full 20-inch barrel, making it easier to maneuver in tight spaces like home hallways or vehicle storage without sacrificing velocity.
- Magazine-Fed Semi-Automatic Action — Why it matters: Reloads faster than tube-fed shotguns because you can swap a loaded magazine in seconds, and the gas system cycles reliably with target loads as well as hunting rounds.
- Integrated Picatinny Rail and Flip-Up Sights — Why it matters: Mount a red dot, holographic, or magnified optic directly without buying extra adapters, and the flip-up sights work as backup zero if batteries die.
- MobilChoke System — Why it matters: Swap chokes to tighten patterns for slugs or open them for birdshot, giving you one gun that adapts to clay targets, home defense, or hunting.
- 5+1 Capacity — Why it matters: Holds five rounds in the magazine plus one in the chamber, enough for most defensive scenarios without making the gun too heavy or bulky.
Who It’s For
This shotgun is for families, youth shooters, and beginners who want a short, easy-to-handle 12 gauge without giving up barrel length. It works well for home defense because the bullpup layout keeps the weight back near your shoulder, reducing muzzle rise. It’s also a good choice for new shooters who find traditional shotguns too long or front-heavy.
Pros and Cons
- Pros: Compact overall length (~30 inches), magazine-fed for quick reloads, integrated rail and sights save money, MobilChoke system adds versatility, affordable price point under $400.
- Cons: Bullpup trigger feel may be slightly heavier or have more travel than traditional shotguns (honest drawback). Some users report the magazine release can be stiff initially, but it loosens with use.
Comparison
| Feature | Rock Island VRBP-100 | Mossberg 590 Shockwave | Kel-Tec KSG |
|---|---|---|---|
| Action | Semi-automatic, gas-operated | Pump-action | Pump-action, dual tube |
| Overall Length | ~30 inches | ~26.5 inches | ~26 inches |
| Barrel Length | 20 inches | 14.375 inches | 18.5 inches |
| Capacity | 5+1 (detachable box magazine) | 5+1 (tube) | 6+6+1 (dual tubes) |
| Choke System | MobilChoke (threaded) | Fixed cylinder bore | Fixed cylinder bore |
| Weight | ~8.2 lbs | ~5.2 lbs | ~6.9 lbs |
| Price | ~$314 | ~$450 | ~$900 |
FAQ
Can the Rock Island VRBP-100 shoot 3-inch magnum shells?
Yes, according to manufacturer specs, it is chambered for 12 gauge shells up to 3 inches. The gas system adjusts to handle both standard 2.75-inch target loads and heavier 3-inch hunting or defensive loads.
Does the VRBP-100 come with a magazine?
Yes, the shotgun ships with one 5-round detachable box magazine. Additional magazines are available separately for faster reloads at the range or in the field.
Is the bullpup design legal in all states?
Federal law treats the VRBP-100 as a standard shotgun because the barrel is over 18 inches and overall length exceeds 26 inches. Some states like California, New York, or Massachusetts have restrictions on bullpup configurations or magazine capacity—check your local laws before ordering.
Can I mount a red dot sight on the VRBP-100?
Yes, the receiver includes an integrated Picatinny rail, so you can mount any standard red dot, holographic, or scope. The flip-up iron sights are already installed and cowitness with many red dots if you prefer a backup system.
How do I clean the VRBP-100?
Field strip by removing the magazine, ensuring the chamber is empty, then pushing out the takedown pins. Clean the barrel and gas piston with solvent, lubricate moving parts lightly, and reassemble. The polymer stock can be wiped down with a damp cloth.
Ready to Handle
If you want a short, fast-handling shotgun that’s easy for the whole family to shoot, the Rock Island VRBP-100 12 Gauge Bullpup Shotgun 20″ 5+1 is a solid choice at a price that won’t break the budget. It’s also a great option for new shooters who want a semi-automatic without the length of a traditional 28-inch barrel. Browse more options in our Semi Auto Shotguns category or check out our Bullpup Shotguns for similar designs. For home defense setups, see our Home Defense Shotguns.
✓ Nationwide delivery to all 50 states
✓ Ships within 1-2 business days
✓ 30-day return policy
✓ Secure checkout
Last updated: April 2026
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