mag springs

[dstroyed]

I was wondering would 170 mag spirng cause problems in a 140 tube as far as reliability? I have some tunned 140 mags with grams 170 kit installed. Another shooter said it could cause some problems.

[yoshidaex]

i use the 13 coil springs that come with the grams followers in my 140mm mag tube and a 11 mm basepad for my 9mm setup. works perfect. though for my 40 i use a 11 coil spring and a 4mm basepad per Bevens recommendation.

[dstroyed]

i think that is what i have in my 9s. Seem to work fine now they are tuned. just checking.

[HSMITH]

You don't need the 13 coil in a 140 but it doesn't hurt anything either. I run a couple SV 140's for my 9mm with 11 coil kits and 11mm basepads, no problems at all. Most of my 140's though use a shorter pad and an 11 coil kit or a Dawson follower and ISMI spring.

[TeamGE]

Mag tube length has nothing to do with how many coils you use by it self. It is the "over-all-length" (OAL) of the tube and base pad combined that my recommendations are based on. Also, what brand of tube you start with will have different results on reliability. STI and SV tubes are two different designs to fit the same gun frame design. STI/SV tubes in the so called "140" length really measure 137mm long (+or- 1mm). If you add a 4mm base pad to this, you get 141mm OAL. If you add an 11mm pad, you get 138mm OAL. My recommend cut off point for using an 11 coil spring is 145mm OAL. The biggest reason for using the 13 coil spring in a 146mm mag (or longer) is to keep the bottom cartridge from slipping past the follower as the cartridge is being loaded past the end of the spacing grooves of a STI mag tube. This problem is common when mag capacity is pushed past 23 rounds of 9mm/.38cal. Older SV tubes will have the same problem, where as the newer SV tubes have been changed to make the spacing groove lower on the tube. A 13 coil spring is the best choice and will give you the best chances of finding a reliable combination of parts. If you choose to use an 11 coil spring in the above describe mag combination, do not load past 22 rounds, and you will still be taking a chance on reliability. Also, a properly "tuned" mag tube with attention to this problem will make a reliable mag.

Edited October 25, 2007 by TeamGE

[yoshidaex]

Beven,

Good to see you can take time off from your already busy schedule to clarify a few items. Will we see you at a local match any time soon? I need to pick some parts up from you .

[TeamGE]

Hiro,

Business has me stuck in the shop, and I only have time to quickly scan benos land for threads that need attention. If you need anything, or have any questions, contacting me directly will get the quickest response. Otherwise, my shooting time is definitely suffering, and I have to plan trips to the range day by day.

Thanks for asking.