These Bolt Carrier Groups are FULLY FUNCTIONAL, but have minor blemishes. SOLD AS IS. No refunds or exchanges.
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 NiB-X (Nickel Boron) 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. Sharps will not guarantee proper function with the use of steel cases, or foreign ammunition.
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: S7 Tool steel, shot peened NiB-X coated (U.S. Patent No. 9,863,729)
Bolt Carrier:S7 Tool steel, shot peened and NiB-X coated
Gas Key: 4130 Steel, attached with Grade 8 hardware, properly staked and NiB-X Coated
Cam Pin: 4340 Steel, Manganese Phosphate coated
Firing Pin: Mil Spec firing pin made of 8740 steel, center‐less ground and Hard Chrome coated
Extractor: 4340 Steel, NiB-X coated
Ejector: S7, shot peened and Manganese Phosphate coated
Extractor Pin: S7, shot peened and Manganese Phosphate coated
Mil-Spec 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 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
Specifically engineered NiB-X nickel boron coating to provide long life, high reliability and easy cleaning and maintenance. The BCG components are coated and polished to reduce fouling adherence. Over 30K rounds in Government protocol endurance testing did not wear the coating off. Especially beneficial in short barrel setups and suppressed platforms.
Friction vs Dry Steel 0.1
Color: Hyper Silver (Polished)