The 6MMBR bolt was developed specifically for High Power competition use but will no doubt see many wildcat combinations built around it. This bolt and extension allow the use of .473 dia. rim cases in a typical AR15 rifle. The 6mm BRX shooting 105 Bergers or 107 SMKs will produce the best exterior ballistics from the AR15 platform. These uppers could be used for  highpower or sniper type competitions, hunting or Varmint shooting.  The 6BRX is pushing 105gr Bergers to 3000fps from a 22" barrel, making it the flattest shooting cartridge to fit a normal AR15.

The lug major diameter was increased to allow a thicker web with a .473 bolt face. Both the bolt and extension were designed with a large radius at the root of the lugs to create as much strength as possible in the assembly. The precision barrel extension is designed with one full inch of thread instead of the common AR15 .620 length of thread to create a much more rigid connection between the barrel and the extension. The extension is one inch in diameter and fits all AR 15 receivers. The bolt is machined from aircraft grade 9310 alloy to increase strength while the extension is made from 8620 as are most extensions.

Sold as a set. $169

LMT enhanced 5.56 bolts sell for $155 without a barrel extension.