The .45 ACP is legendary. John Moses Browning's creation was used to fight several wars and continues to be one of the world's most popular calibers. Right To Bear has the parts you need to build a .45 ACP on an AR platform. Start with a dedicated 45 ACP AR lower. This is a restricted item and must be shipped to an FFL. The magwell is cut to accept Glock mags. It uses a standard AR lower parts kit.
Pick your 45 ACP AR barrel length, go for 5" or 8" for a pistol or get maximum performance with a 16" carbine barrel. Match this to a 45 ACP AR upper that also pulls duty as a 9mm upper. The 45 ACP bolt carrier group has a blowback action, so a gas tube and block are not needed. Complete your build with 45 ACP accessories, including maintenance and repair kits.