Tactical Springs (Sprinco) M4/M16 Extractor Upgrade Kit - Triple Pack

CONSTRUCTION SPECS EXTRACTOR SPRINGS: Chrome Silicon Wirestock Heat Treated, Stress Relieved, and Cryogenic Processed Post Winding Impregnation / Plating 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(TM) 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. 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 750degF D-Fender(TM) rings are NOT recommended for use with our 5-Coil extractor springs. Plug & play - May easily be the only extractor springs needed for the life of your bolt!!