KelTec KP50 5.7x28mm Pistol

The KelTec KP50 5.7×28mm Pistol is one of the most unusual and capable semi-automatic handguns on the civilian market. With a 50-round capacity using standard FN P90 magazines, a threaded barrel for suppressor-ready use, and a full-length Picatinny rail, the KP50 delivers the firepower of a personal defense weapon in a legal pistol configuration. At $699, it offers serious capability for suppressor hosts, range enthusiasts, and collectors who want something genuinely different from the standard handgun lineup.

Key Features of the KelTec KP50

KelTec has built a reputation on unconventional designs that deliver real-world value, and the KP50 is no exception. This pistol pulls its design DNA directly from the FN P90 — a legendary personal defense weapon used by military and law enforcement worldwide — and translates it into a civilian-legal semi-automatic pistol that fires the fast, flat-shooting 5.7×28mm cartridge.

50-Round FN P90 Magazine Compatibility: The KP50’s party trick is its use of standard FN P90 50-round magazines. These top-loading, horizontally mounted magazines are perhaps the most recognizable feature of the P90 platform, and the KP50 retains them. Fifty rounds of 5.7×28mm in a single magazine is a remarkable capacity for a pistol — far beyond what any conventional handgun offers. The magazine sits on top of the action in a bullpup configuration, feeding downward into the breech. Reloading takes practice, but the high capacity means you’ll be doing it far less often.

Bullpup Layout: The KP50 uses a bullpup configuration, placing the action behind the grip rather than in front of it. This means a longer barrel (5.1 inches) packed into an overall package just 15.7 inches long. The result is better ballistic performance from the 5.7×28mm cartridge without the awkward length of a conventional pistol with the same barrel. The layout also contributes to excellent balance — the weight distribution keeps the muzzle steady under sustained fire.

Threaded Barrel: The 5.1-inch barrel is threaded from the factory, making the KP50 an excellent suppressor host right out of the box. The 5.7×28mm cartridge is inherently subsonic-capable with the right ammunition selection, and a suppressed KP50 running subsonic loads is genuinely hearing-safe — a combination that’s hard to beat for home defense applications or range use without hearing protection. No gunsmithing required to thread the barrel: just mount your suppressor and go.

Full-Length Picatinny Rail: A full-length Picatinny rail runs the length of the KP50’s top — a significant advantage for accessory mounting. Mount a red dot or reflex sight for rapid target acquisition, then add a flashlight or laser on the side rail. The KP50’s bullpup layout and long rail give you genuine flexibility in how you configure the pistol for your use case.

Ambidextrous Controls: KelTec designed the KP50 with ambidextrous controls throughout, including the charging handle and safety. Left-handed shooters are fully accommodated without modification — a feature that’s still far from standard across the industry.

5.7×28mm Cartridge: The 5.7×28mm round was designed by FN specifically for the P90, optimized for low recoil, high velocity, and performance against light body armor (in military loadings). In civilian loadings, it’s a fast, flat-shooting round with minimal recoil that’s effective for both personal defense and small-game hunting. The high velocity translates to a flat trajectory that makes hits at extended pistol distances easier than with conventional handgun cartridges.

Full Specifications

Specification	Detail
Model	KelTec KP50
Caliber	5.7×28mm
Action	Semi-automatic, bullpup layout
Barrel Length	5.1 inches — threaded
Capacity	50 rounds (FN P90 magazines)
Overall Length	15.7 inches
Weight (Empty with Mag)	3.7 lbs
Frame Material	Polymer
Rail	Full-length Picatinny
Controls	Ambidextrous
Magazine Compatibility	FN P90 50-round magazines
Barrel Threading	Yes — suppressor ready
Our Price	$699.00

Who Is the KelTec KP50 For?

The KP50 is purpose-built for shooters who want maximum capacity in a legal pistol configuration. If you’re building a suppressor-ready home defense setup or simply want to spend more time shooting and less time reloading on the range, the 50-round magazine capacity changes the equation entirely. Suppressor enthusiasts will particularly appreciate the threaded barrel and the 5.7×28mm cartridge’s subsonic ammunition availability — this combination produces one of the most practical suppressed pistol setups available at this price point. Browse our full handgun selection for comparison options.

Collectors and enthusiasts drawn to unusual designs will find the KP50 fascinating both mechanically and historically. Its P90 lineage connects it to one of the most distinctive military firearms of the last 30 years, and the bullpup layout attracts shooters who are tired of conventional pistol configurations. The full-length Picatinny rail and ambidextrous controls mean it’s also genuinely usable, not just a range curiosity. This is a semi-automatic pistol that earns its keep whether you’re running a suppressor class, a 3-gun match, or simply building a collection of distinctive American-made firearms.

Law enforcement and security professionals looking for a high-capacity backup or truck gun may find the KP50’s 50-round capacity and 5.7×28mm ballistics appealing for scenarios where sustained fire capability matters. The compact bullpup layout packs a longer effective barrel into a manageable package, and the low recoil of the 5.7mm cartridge allows rapid, accurate follow-up shots. Explore our full range of pistol options if you’re comparing platforms before committing.

Pros and Cons

Pros:

• 50-round capacity using FN P90 magazines — unmatched in the pistol category
• Threaded barrel from the factory — suppressor-ready without additional cost
• 5.7×28mm cartridge is low-recoil and effective with a wide range of loadings
• Full-length Picatinny rail for optics and accessories
• Ambidextrous controls — genuinely left-hand friendly
• Bullpup layout delivers a longer barrel in a compact package
• Made in the USA by KelTec

Cons:

• Unconventional operation requires a learning curve — not ideal as a first pistol
• P90 magazines can be harder to source than standard pistol magazines
• At 3.7 lbs with magazine, it’s heavy for a pistol
• 5.7×28mm ammunition is more expensive than 9mm
• Overall length of 15.7″ makes holstering impractical

Frequently Asked Questions

Q: What magazines does the KelTec KP50 use?
A: The KP50 uses standard FN P90 50-round magazines. These are available from FN and several aftermarket manufacturers. The horizontal top-loading design is unique to the P90/KP50 platform and holds 50 rounds of 5.7×28mm in a compact, low-profile configuration.

Q: Is the KelTec KP50 suppressor-ready?
A: Yes — the KP50’s 5.1-inch barrel is threaded from the factory for direct suppressor attachment. No gunsmithing required. Combined with subsonic 5.7×28mm ammunition, a suppressed KP50 is one of the quietest and most practical suppressed pistols available.

Q: What is the effective range of the KP50?
A: The 5.7×28mm cartridge from a 5.1-inch barrel is effective and accurate at 50–100 yards in most shooters’ hands. The flat trajectory and low recoil make it easier to stay on target at extended handgun distances compared to heavier, slower pistol calibers.

Q: How reliable is the KelTec KP50?
A: The KP50 has a solid reliability track record with quality 5.7×28mm ammunition. Like all KelTec products, it performs best with name-brand factory ammunition. A break-in period of 200+ rounds is recommended before relying on the platform for duty use or personal defense.

Q: Is the KelTec KP50 legal to own?
A: In most U.S. states, yes — the KP50 ships as a legally classified pistol. It does not fall under the NFA as long as you do not add a stock or vertical foregrip. Some states have restrictions on magazine capacity that would limit use of the 50-round P90 magazine; check your local laws before purchasing.

A Truly Unique Semi-Auto Pistol

The KelTec KP50 isn’t for everyone — and that’s exactly the point. It’s engineered for shooters who want maximum capacity, suppressor-ready capability, and a platform that stands apart from the crowd of conventional handguns. At $699 with a threaded barrel and 50-round magazine included, it represents genuine value for what it delivers. If the KP50 matches your use case, you’ll find it hard to go back to a conventional pistol.

Last updated: March 2026