The Low Mass Sharps Xtreme Performance Bolt (XPB) Carrier Group Complete is comprised of our patented Relia-Bolt™ and our Special Low Mass Balanced Bolt Carrier. Low Mass Carrier is 1.7 ounces lighter than the Full Mass Carrier. Made specifically for competition shooters. The XPB undergoes a 24-hour thermal cycle proprietary heat treatment, and is finished with the DLC (Diamond Like Carbon) Coating. 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. Weight: 9.5 oz
Sharps will not guarantee proper function with the use of steel cases, or foreign ammunition.
Color: Carrier and Bolt DLC (Diamond Like Carbon) Black
Order cancellations may incur a 15% restocking fee. Please see return section
Limited Lifetime Warranty
If any SRC Balanced Bolt Carrier or Relia-Bolt™ is found to have manufacturer defects, SRC will repair or replace it at no charge. Manufacturer defects include broken lugs, out of spec parts or defective parts. Although our BCG is Mil-Spec, there are so many variables, sometimes a little troubleshooting, or fine tuning of parts may be required for proper functionality. Before a part is replaced or refunded, SRC reserves the right to inspect and test part(s) in question to determine if it is defective.
Bolt and carrier: S7 tool steel, shot peened and DLC coated (U.S. Patent No. 9,863,729)
Gas key: 4130 Steel. attached with Grade 8 hardware, properly staked and DLC coated.
Cam pin: 4340 Steel, Manganese Phosphate coated
Firing pin: Mil spec made of 8740 Steel, center-less ground, and Hard Chrome coated.
Extractor: 4340 Steel, Manganese Phosphate coated
Ejector: S7, shot peened and Manganese Phosphate coated
Extractor pin: S7, shot peened and Manganese Phosphate coated
Mil-Spec Extractor and Ejector springs, Firing pin retaining pin, Gas Rings
Batch MPI and HPT tested
Tensile Strengths of 1550-1600 mpa, or 220,000-235,000 psi.
Toughness over 200ft/lb Charpy C-Notch
HRC of 46 yields a 15% increase in hardness at the same toughness comparing to Carpenter 158 & 9310.
Technical Data on DLC Coating
Coating thickness: 2-4 Microns
Hardness HV 0.05: HRC 80+
Deposition methid: PVD UBM/PACVD
Friction vs Steel, dry 0.1
Made in the USA