The Sharps Xtreme Performance Bolt (XPB) Carrier Group Complete is comprised of our patented Relia-Bolt™, and our Balanced Bolt Carrier. Both are machined out of S7 tool steel. The XPB undergoes a 24-hour thermal cycle proprietary heat treatment and is finished with ZrN (Zirconium Nitride) Coating Bolt Carrier and DLC Bolt.  

The XPB carrier displays the SRC logo machine cut and is visible when the ejection port door is open. The XPB fits standard AR-15/M16/M4 rifles chambered in .223/5.56, Sharps 25-45, and 300 Blackout calibers. Carrier is FDE (Flat Dark Earth) Brown. Bolt is DLC (Diamond Like Carbon) Black.

Technical Specification

Why S7 Tool Steel?

S7 has excellent shock absorbing properties which provide superior impact resistance when being utilized in the construction of Sharps Bolt Carrier Groups. S7 demonstrates high strength and toughness as well as a resistance to softening at moderately high temperatures, i.e. operating temperatures not exceeding 1000°F. 

The properties we as shooters look for in an AR platform BCG, are hardness and wear resistance.  S7 provides such attributes when heat-treated properly. Sharps has found that the key benefits from S7 tool steel are higher tensile strength and toughness which translate to longevity of use, i.e., a higher number of cycles the bolt can handle before it fails.

• MPI and HPT tested
• Tensile strengths of 1550-1600 mpa, or 220,000-235,000 psi.
• Toughness of over 200 ft./lb. Charpy C-Notch
• HRC of 46 yields a 15% increase in hardness at the same toughness comparing to Carpenter 158 & 9310
• Mil-Spec Extractor and Ejector Springs, Firing Pin Retaining Pin, Gas Rings