140mm Mag Spring 120% 11 Coil

2011 17rd and 20rd round magazines use the same length spring. Owners often find that this results in less than optimal spring power in their 20rd magazines, which can result in feed inconsistencies and failure to lock back on empty. Our 11 coil 120% spring for 20rd magazines solves this issue and also allows you to add a +3 extension to your 140mm 20rd 9mm magazine tubes and your 140mm 13rd .45acp magazine tubes.  These springs are manufactured by AQS the factory that makes springs for Noveske, Apex, Sig, CMMG, POF-USA. We lucked out and our shop just happened to be ten minutes from their factory.  Specifications Compatible with Staccato/Mac/Tisas/Kimber/Prodigy 140mm tubes Material: 17-7 Stainless Steel