Underworld Arms
140mm Mag Spring 120% 11 Coil
140mm Mag Spring 120% 11 Coil
Couldn't load pickup availability
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
I replaced the stock springs on Tisas Night Stalker 17-round and Atlas 20-round mags with the 140mm 120% springs, and they have worked perfectly.
Prompt shipping. Springs are great in my magazines for my Kimber 2k11. Ordered the MK2 mag extensions today
Perfect fit in 20 round Prodigy mags. Much better tension than stock springs. Fed rounds perfectly no issues.
No more feeding problems with these bad boys in my mags hehe
Great quality. I'll be buying a 5 pack of these at a time when I purchase new Prodigy mags. It definitely helps with slide lock back.
