Sprinco USA Spring Upgrade Kit-XP 5-coil Extractor Spring/inner Spring

Sprinco’s Extractor Springs are made of chrome silicon wirestock that has been heat treated, stress relieved, and cryogenic processing post winding. The springs are also plated with re-micronized molybdenum disulfide formulation. ADVANTAGES: XP 5-Coil spring has a heavier spring load than OEM springs, thus negating the need for a D-Fender™ ring or adding CRANE Viton O-Rings Use 5-Coil spring with either black extractor spring insert OR CRANE Viton O-Rings, but not both Enhanced 4-Coil springs maintain an extended duty cycle load of a NEW Mil-Spec spring and is recommended for use in 18""+BBL lengths for those who retrieve their brass for reloading While the XP 5-Coil spring is totally reliable for all 5.56 BBL lengths, it can be aggressive on case rims in 18""+length BBL rifles, and may be too strong for some bolts with extremely tight bolt face tolerances Extreme duty cycles provided while maintaining performance specifications Unaffected by heat up to 750°F D-Fender™ rings are NOT recommended for use with our 5-Coil extractor springs. Dual spring XP .308 extractor spring sets may be used with or without CRANE O-rings. May be required for use in DPMS G2 Bolts for full-auto use. Plug & play - May easily be the only extractor springs needed for the life of your bolt!!