Running an AR-15 in 22 Long Rifle

See also: 223 Remington vs 5.56mm vs 22 Long Rifle.

Conversion kits vs Dedicated Upper

Fjold, of Calguns, brought up that the 22LR projectile is actually slightly smaller in diameter than a 223 projectile. This means that, while it will fire more or less reliably from an AR-15 barrel, there will be a degree of "slop" involved, which will greatly reduce the accuracy found by using a Ceiner or other conversion kit and a standard AR-15 barrel. It is recommended, if accuracy is even remotely of concern, to use a dedicated upper instead of a conversion kit.

Dimension	22LR SAAMI spec	223 SAAMI spec
Bore diameter	0.217"	0.219"
Groove diameter	0.223"	0.224"

22LR AR uppers

• CDNN offers the V-22 upper for $260. STRONGLY recommended in CA - it cannot be readily removed from the weapon once installed, and doesn't permit the installation of standard AR mags.
• Bushmaster has a 22LR upper out for around $380 (seen online)
• DPMS has a 22LR upper with an optional 17HMR2 barrel for $400ish. Available via http://www.cheaperthandirt.com/

-- SeanNewton - 28 Jan 2006