Wilson Combat Bullet Proof Extractors are machined from solid bar stock alloy steel and then specially heat treated to optimum hardness and cryogenically treated for long lasting tension and toughness to resist chipping or breakage. It requires minimal fitting for proper function and often will drop in some guns with only final tensioning required. Series 70 extractors lack the machined cut which allows the firing pin lock plunger to be installed and therefore cannot be used in Series 80 guns. This Bullet Proof 1911 Extractor for 70 Series 45 ACP is fully machined from S7 tool steel (a Wilson exclusive) which is shock resistant with excellent toughness and high strength (tensile strength of 275,000 PSI), along with good wear resistance.