Brownells Gun Techs Caleb and Steve are sharp as new thumb tacks and even more adept at bursting balloons of firearm misinformation. Today they tackle the notion that any ARtype rifle chambered in 7.62 NATO or .308 Winchester is an AR10. Many people who think they own an "AR10" actually have what's generically called an "AR308". The AR10® is a specific rifle made by the Armalite® company, which owns the AR10® name as a registered trademark. So ONLY that Armalite rifle can be legitimately called an AR10®. ("AR15" is a nontrademarked, public domain designation for the smaller rifle usually chambered in 5.56 NATO or .223 Remington.) The big deal for an AR308 owner is that AR10® parts are NOT necessarily interchangeable with parts for the DPMS LR308 or other AR308 rifles. Significant differences include the upper receivers, barrel extensions, handguard mounts, bolt headspacing, gas tubes, and buffers. The fire control groups, dust covers, pistol grips, muzzle devices, and receiver extensions (buffer tubes) WILL interchange, as will the magazines (except for some very old AR10s that used FN FAL mags). If you own an AR10®, Armalite will be your main source for parts, though some aftermarket parts makers do offer AR10® specific handguards and the like. One problem is that some makers of AR308 components are careless and say their parts are for the "AR10". Have you had compatibility problems with AR10 vs AR308 parts? Tell us about it in the comments!