In the United States, M203 grenade launcher attachments fitted with the standard rifled 40mm barrel are classified as "Destructive Devices" under the National Firearms Act part 26 U.S.C. 5845, 27 CFR 479.11,[26] because they are a "non-sporting" firearm with a bore greater than one-half inch in diameter. M203s are relatively common on the civilian NFA market. New M203s sell for approximately $1,750 to $2,000 plus a $200 transfer tax, and new manufacture 40mm training ammunition is available for $8 to $10 per cartridge, as of March 2008. High explosive 40mm grenades are available for $400 to $500 per cartridge; however, they are exceedingly rare on the civilian market, as each grenade constitutes a Destructive Device on its own, and must be registered with the Federal government, requiring payment of a $200 tax and compliance with storage regulations for high explosives. There are also sub-caliber adapters available for the 40mm M203 (and M79) grenade launchers, which will allow the use of standard 12 gauge shotgun shells[27] and .22 Rimfire ammo.[28]