Carrier Assembly: The flared rear of the enhanced bolt carrier is designed to reduce carrier tilt/cant during recoil and increasing reliability by strategically relocating key bearing surfaces.
The STT enhanced carrier has fewer points of contact resulting in less friction area and the increase in mass ensures proper gas pressures and increases dwell time, thus improving extraction while shooting suppressed or short-barreled rifles (SBRs)
Bolt Assembly: The Bolt is “true” Mil-Spec dimension and external surfaces are CNC ground after heat treat for a precision fit. The bolt is machined to AR-10 .308/6.5 Creedmoor. STT bolts are held to the highest possible tolerance possible. Outside critical dimensions held to .0005”. The “trumpet” area behind the gas rings, where carbon normally collects, is precision CNC Ground after heat treatment, to ensure as smooth of an area as possible, easing clean up, and longevity.
BLACK NITRIDE is a process commonly referred to anonymously with SBN (Salt bath nitride) and sometimes QPQ (quench polish quench). All of these are a form of nitrocarburizing which is a chemical hardening of steel in short.
Black Nitride Finish Benefits
Like all San Tan products, this is exceptionally well made, much more durable than the standard Mil-Spec AR15 BCG and includes STT’s Satisfaction Guarantee and Lifetime Warranty.