The National Firearms Act (NFA) requires that all "silencers" (sound suppressors) be registered including paying a $200 tax. Secret draft documents obtained by Nevada Carry show that the ATF is planning on reclassifying many common rifles as integrally suppressed. That means the rifles inherently have a sound suppressing ability in their original design without needing a separate suppressor (silencer) to be attached. This will require that tens or even hundreds of millions of rifles be registered with the ATF or owners will become federal felons.
The ATF defines a "silencer" as anything that reduces or suppresses the sound of a gunshot. Up until now, regulated suppressors (silencers) acted like an auto muffler where pressurized exhaust gases expanded slowly in a chamber to be released to the atmosphere. The controlled expansion, cooling, and slow release of the gas reduced the sound. In guns, this can reduce the sound level by up to 30 dB.
With this new classification, a rifle barrel itself may be considered a suppressor. This is based on the fact that longer barrels allow powder to burn for a longer time and more completely in the barrel before exiting. The gas volume is also lower in longer barrels which also contributes to a lower sound profile than in shorter barrels. If you've ever shot an 8" AR pistol you know what they mean. A 16" rifle is much quieter. It is the fact that the longer barrel makes the gunshot less loud that the ATF is objecting to.
So, the ATF is arguing that For AR-15s in particular, since many of the designs are based on the M4 carbine, a 14.5" barrel is taken into consideration, which means the common 16" barrels will, in 120 days, be considered "silencers" under the NFA.
The ATF has done this before, ruling that the modest reduction of the gunshot sound level from the unique muzzle device of the XM177 CAR-15 made the muzzle device into a suppressor. This made these already short-barrel rifles (SBRs) "two-stamp" guns that required that their muzzle devices also be registered "silencers." The guns were withdrawn from the market in this guise and many were modified or surrendered.
This ruling will create a chicken-egg situation where to get a rifle like a "M-forgery" M4-type AR-style down to a non-silencer configuration under 16" in barrel length would require the weapon to be registered as a short-barreled rifle. It's unclear if Colt civilian AR derivatives from the 20" barreled M16 would be affected. Other rifles may be affected too if their original design was less than the current barrel length now on the weapon.
Clayton E. Cramer
Gun Free Zone
The War on Guns
The View From Out West