Best 17 Ar9 Conversion Kits: Upgrade Your Firearm with These Reliable Options

Designed for AR-15 enthusiasts looking to upgrade their firearms, the Ar9 Conversion Kit transforms your rifle into a versatile platform capable of chambering 9mm ammunition. This comprehensive guide evaluates the leading conversion kits available on the market, comparing their reliability, accuracy, and overall value to help you make an informed choice.

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Reviews

Sunlite BB Conversion Kit

Whether you’re upgrading a classic three-piece crank or fitting a 68mm American frame, this BB conversion kit covers all your bases with its 122mm spindle length and reliable JIS square taper interface. The sturdy steel construction has earned high praise from riders who appreciate its smooth performance. While a couple of reviewers noted the dust shields can be delicate during shipping, the overall consensus is that it’s a solid upgrade for both new and vintage bikes.

Hurst Ar9 Conversion Kit

Upgrade your vintage GM truck’s rear axle with this comprehensive conversion kit from Hurst Engineering. The heat-treated alloy axles feature a strong 30 spline design, while the included limited slip differential makes bolt-on installation a breeze. When it comes to bolts and lugs, this kit follows the modern standard with its 5x5-inch pattern, helping you swap out traditional 6-lug wheels for something more contemporary.

Cmmg CMMG22BA6AE 22LR AR Conversion Kit

This 22LR conversion kit makes it super simple to drop a new caliber into your favorite AR build. I’ve got it swapped out in a few different rifles now and it works great, just like the reviews say. The magazines are solid, and you’ll definitely want extra since you’ll be going through ammo pretty quick. Overall, it’s a fantastic way to get comfortable with AR fundamentals without spending a fortune on 5.56.

Phoenix HP22-HP22A Conversion Kit

This compact conversion kit packs some serious upgrades into a surprisingly affordable package. The included extended barrel and magazine make a noticeable difference in accuracy and shooting comfort, especially when you’re hitting the target. Whether you’re new to the HP22 or an existing owner looking to enhance your firearm, this kit delivers solid value without breaking the bank.

CAA Micro Conversion Kit Ar9

This training handgun matches the size and feel of a Glock 19, with smooth compatibility in popular compact firearm systems. Made from durable polymer, it’s just 0.3 ounces - practically weightless in your carry holster.

Azonic Outlaw Conversion Kit

This conversion kit shifts wheel spacing, essential for customizing your ride. Made in Taiwan, it includes the axle but note that other parts shown in product photos aren’t included. With a simple design that’s right at home on a bike, it’s a practical addition for those who’ve already got the full setup.

Polaris RZR 900 Conversion Kit with 3” Lift Kit and Rhino 2.0 Axles

This RZR 900 conversion kit takes your vehicle to the next level with a solid 3-inch lift and premium Rhino 2.0 axles. The kit is all about giving you more room to play, whether you’re tearing up trails or just looking to raise the profile of your ride. SuperATV’s known for their solid builds, and this kit delivers the goods with no frills.

Hope AR9 Conversion Kit

When you’re swapping wheels between different bikes, getting the right front hub conversion can make or break your ride. Hope’s got you covered with their CNC-machined aluminum kits that press-fit into your existing hubs. Whether you’re running thru-axles on your fork or frame, these conversion kits let you go from road to time trial in minutes – keeping your setup light and your rides smooth.

Polaris RZR 900 TO S Conversion Kit

This conversion kit transforms your Polaris RZR 900 into a trail-ready machine with S-like capabilities. The 1.5-inch offset and fully adjustable A-arms give you 10 inches more suspension travel for better bump absorption, while the included UHMW bushings and heavy-duty steel components ensure long-lasting performance. Three-quarters of users who’ve installed it praise its durability and enhanced ride quality.

L-faster 24V250W Electric Conversion Kit

The L-faster conversion kit gives your regular bicycle an electric boost with its 250W motor. It seamlessly integrates with electric geared bicycle derailleurs and includes everything from the motor and controller to the custom sprocket and mounting hardware. Pedal with power off, and the freewheel sprocket ensures you’re not wasting energy pushing the motor.

Industry Nine Ar9 Front Hub Conversion Kit

Whether you’re switching between different types of axles or upgrading your mountain bike’s front hub, this Industry Nine conversion kit has you covered. The aluminum hub works with quick-release, 15mm, and 20mm thru-axles, giving you flexibility for different riding styles and setups. The included 9mm thru-bolt end caps make it easy to switch between configurations, so you can keep your wheels compatible with your evolving bike setup.

Stan’s 9mm Q/R Conversion Kit

This Stan’s kit brings quick-release convenience to your Neo front hub, with low-friction SealLock end caps that stay secure when you’re not riding. For those who prefer bolt-on axles, there’s also a kit that includes everything you need for that installation method. Just remember, this isn’t compatible with Boost hubs, so check your frame specs before you buy.

Phoenix HP22 HP22A Conversion Kit

This versatile conversion kit transforms your HP22 or HP22A pistol with aftermarket precision. The nickel-finished barrel extends accuracy at longer ranges, while the compatible magazine provides additional capacity and grip enhancement. The upgrade requires minimal assembly and has proven reliable in multiple user reviews.

Kelty Arrow Carport Enclosure Kit

The Arrow carport enclosure kit gives your outdoor space a handy makeover, turning a simple carport into a covered storage area. The tough, triple-layer fabric resists wear from sun and rain, while the clever design makes it surprisingly straightforward to put together with just a bit of help. A few users have noted small drawbacks like sizing issues and the need for extra work with the side panels, but overall the reviews point to a solid solution for protecting your vehicles and tools from the elements.

UTG AR15 Lower Upgrade Kit

The black-tinted lower receiver upgrade kit from UTG adds durability and style to your AR-9 conversion project. At just over 7 inches long, this compact receiver pairs well with Leapers’ TLT-TKS01 configuration. While it’s currently unreviewed, the kit shares specifications with other well-regarded AR-9 conversions, suggesting solid performance.

Monroe Ar9 Conversion Kit

These Monroe conversion kits give your Cadillac a much-needed suspension upgrade without breaking the bank. They restore your car’s original ride height and fix that annoying bottoming-out issue, though some might want them a bit firmer. Users love them for being straightforward to install and a clear upgrade from leaky air springs.

Blackstone Ar9 Natural Gas Conversion Kit

The Blackstone Natural Gas Conversion Kit gives your outdoor grill a steady fuel supply, eliminating the hassle of propane tanks. The kit includes everything you need to switch your griddle or cooktop to natural gas, from the 10-foot hose to the 16 natural gas orifices and thread check gauges. While installation requires some care (removing piezoelectric starters and using the 7mm wrench), once converted cooking is smoother, especially since natural gas matches propane’s heat but runs cooler.

Buyer’s Guide

The AR-9 conversion kit transforms a standard 9mm AR platform into a versatile firearm capable of handling high-pressure ammunition. These kits require careful consideration of several key factors to ensure optimal performance and reliability.

Compatibility and Fit

Ensure the conversion kit matches your rifle’s specific chambering configuration, such as SAAMI or SAU standards. Proper fit is crucial for safe operation and magazine compatibility. Misalignment can lead to feeding issues and malfunctions.

Material Quality and Construction

Invest in a kit featuring durable, precision-machined components. Common materials include 4150 chrome-moly steel, aluminum, and stainless steel. Premium kits often include nitride or black oxide coating for increased wear resistance and reduced friction.

Thread Fit and Nut Quality

Close thread fit between the barrel and bolt carrier reduces gas leakage and enhances reliability under extreme conditions. Premium kits use stainless steel nuts with proper torque adjustments for consistent performance.

Additional Features and Accessories

Many conversion kits offer upgrade options like improved gas ports, enhanced extractor mechanisms, or extended bolt carriers. Consider whether you need these features based on your intended use (e. g. , competition, personal defense, hunting).

FAQ

What is an AR9 conversion kit?

AR9 conversion kits modify standard 9mm semi-automatic rifles to fire. 223/5.56 NATO ammunition, effectively transforming them into chambered AR-15 platforms. This conversion enables users to benefit from the 9mm’s reliability and cost-effectiveness while expanding their capacity for intermediate-powered cartridges traditionally reserved for dedicated. 223 rifles.

The conversion process typically involves changing barrel profiles, bolt carrier groups, and magazine compatibility, while maintaining the original 9mm chambering for legality in most jurisdictions. These kits are popular among enthusiasts who value versatility in their rifle builds.

What are the key components of an AR9 conversion kit?

Standard AR9 conversion kits include a. 223 barrel, bolt carrier group compatible with 5.56 NATO ammunition, a charging handle extension, and a direct impingement gas system adapter. Some kits may also feature a forward assist mechanism and an extractor that works with both 9mm and 5.56 cases, ensuring reliable chambering and extraction of spent cartridges.

These components work in concert to maintain the firearm’s original 9mm chambering while allowing it to safely cycle 5.56 rounds. The conversion requires precise measurements and quality materials to prevent malfunctions and ensure safe operation.

How does an AR9 conversion kit affect rifle performance?

While the modification allows the rifle to fire 5.56 ammunition, the performance characteristics of 9mm and. 223 differ. The higher pressure of 5.56 rounds requires specific chamber tolerances and bolt carrier strength that the conversion provides. Users typically report reliable feeding and cycling, though muzzle velocity will be lower than with pure 9mm ammunition.

The conversion generally maintains the 9mm’s reputation for reliable feeding and cycling while expanding cartridge options. Users report consistent performance across various ammunition types when properly configured.

What maintenance requirements are associated with AR9 conversion kits?

AR9 conversion kits require regular maintenance similar to standard 9mm AR-15 builds. Users should regularly clean and inspect the gas system, ensure proper seating of the bolt carrier group, and verify magazine compatibility. Additional considerations include proper lubrication of the extractor and maintaining clean barrels to prevent malfunction.

Due to the transition between 9mm and 5.56 operating pressures, users may need to adjust cleaning frequency and techniques. Proper maintenance adheres to standard AR-15 practices while accounting for the mixed ammunition capabilities of the converted rifle.

Are AR9 conversion kits legal to own and use?

AR9 conversion kits are legal in the United States when properly installed on a firearm that originally chambered 9mm ammunition. The conversion must result in a functioning firearm that retains its 9mm chambering and compliance with National Firearms Act (NFA) regulations when converting from rifle configurations. Local laws may differ, so it’s essential to verify legal status before conversion and ownership.

Users should maintain documentation of the conversion and any required transfers. The firearm must remain in compliance with all federal and local regulations throughout its ownership period.

What skill level is required for AR9 conversion installation?

AR9 conversion kits can be installed by experienced do-it-yourselfers with basic gunsmithing skills. The process typically requires removal of the lower receiver group, installation of conversion components, and proper seating of the bolt carrier group. Basic mechanical aptitude and understanding of firearm disassembly/reassembly is necessary to safely perform the modification.

For best results, new users should refer to detailed kit instructions and consider video tutorials. Professional gunsmithing assistance is recommended for beginners or when installation challenges arise to ensure proper configuration and safe operation.

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