The CMMG 22LR 16.1" M4 Replacement Barrel & Bolt Group Kit gives you a quick, affordable way to add a dedicated .22LR upper to your existing AR platform rifle. Instead of building or buying an entirely new rifle, this kit lets you convert a standard M4-pattern upper receiver into a .22 shooter — perfect for training, plinking, or stretching trigger time on a budget. You get everything except the magazine: a 16.1" barrel chambered in .22 Long Rifle and a matched bolt group, ready to drop in and run.

This kind of conversion setup is especially popular with shooters who want a lighter recoil alternative for practice or introducing new shooters to the platform without the cost and complexity of a completely separate rifle. The .22LR also lets you shoot longer strings before fatigue sets in, and ammunition costs stay low — making it genuinely practical for high-volume range days.

To get the most reliable function from this kit, CMMG recommends using a round-style hammer in your lower (notched hammers can create feeding issues) and running 36-grain plated nose ammunition, which has proven to be the most consistent choice in this platform. All you'll need to add is a .22LR magazine to get shooting.

The CMMG 22LR 16.1" M4 Replacement Barrel & Bolt Group Kit gives you a quick, affordable way to add a dedicated .22LR upper to your existing AR platform rifle. Instead of building or buying an entirely new rifle, this kit lets you convert a standard M4-pattern upper receiver into a .22 shooter — perfect for training, plinking, or stretching trigger time on a budget. You get everything except the magazine: a 16.1" barrel chambered in .22 Long Rifle and a matched bolt group, ready to drop in and run.

This kind of conversion setup is especially popular with shooters who want a lighter recoil alternative for practice or introducing new shooters to the platform without the cost and complexity of a completely separate rifle. The .22LR also lets you shoot longer strings before fatigue sets in, and ammunition costs stay low — making it genuinely practical for high-volume range days.

To get the most reliable function from this kit, CMMG recommends using a round-style hammer in your lower (notched hammers can create feeding issues) and running 36-grain plated nose ammunition, which has proven to be the most consistent choice in this platform. All you'll need to add is a .22LR magazine to get shooting.