Sierra Bullets 1575C: Shooters around the world will appreciate the accuracy and extreme long range performance of our new 6mm 110 grain HPBT. A sleek 27 caliber elongated ogive and a final meplat reducing operation provide an increased ballistic coefficient for optimal wind resistance and velocity retention. To ensure precise bullet to bore alignment, a unique bearing surface to ogive junction uses the same 1.5 degree angle commonly found in many match rifle chamber throats.