CZ open 9mm

[TeamGE]

Round counts that I have been able to achieve so far:

Open Division legal mag length at 171.25mm,

9mm = 29 rounds (SP01 & TS tubes)

Beven, this doesn't make sense to me, you can get the same amount of rounds into a small frame mag as you can get into a TS mag? The most I've heard of in a small frame big stick is 26? 29 sounds right for a TS big stick with extended basepad and modified follower.

Hello kneelingatlas,

Maximum round count with 100% reliability is obtained when all the parts of the mag are in correct form. Having the right spring and follower for one, the tube correctly shaped for two, and the tube lenth fitting the gauge. This means that the extended base pad used to get that perfect fit to the gauge must have a bottom that is perpendicular to the back of the tube. In other words, if the mag does not stand straight up on a table top, you are loosing room and will suffer a round count loss.

My small frame and large frame CZ mags fit the 171.25 mark with custom made base pads that will stand straight up on its base. Both small and large frame mags will hold 29 rounds.

Best Regards,

Beven Grams

Edited November 13, 2012 by TeamGE

[kneelingatlas]

Thanks for the reply Beven (and proving the thread is never dead!), that's amazing you can get 29 into a small frame mag, the same mag should fit a small frame Tanfoglio right?

Now that I think about it, the 9mm TS mags have ribs which pinch in the stagger to nearly the same width as the small frame right? I guess the big benefit of the wide mag is the .40.

[TeamGE]

Thanks for the reply Beven (and proving the thread is never dead!), that's amazing you can get 29 into a small frame mag, the same mag should fit a small frame Tanfoglio right?

Now that I think about it, the 9mm TS mags have ribs which pinch in the stagger to nearly the same width as the small frame right? I guess the big benefit of the wide mag is the .40.

I have not tried to fit the small CZ mag into a Tanfoglio frame. I would guess that it will not.

You are correct on what the control ribs are for in the TS 9mm mags. And, the 40cal mags do not have control ribs.

[Jon Merricks]

He lives! Thanks for sharing Beven.

[Glk21C]

Thanks for the reply Beven (and proving the thread is never dead!), that's amazing you can get 29 into a small frame mag, the same mag should fit a small frame Tanfoglio right?

the CZ-75 mags will work in a small frame tanfoglio. However, some tuning is required for reliable feeding, especially a big stick. I had the best luck with the Mec-gar CZ-75 mags in my small frame tanfoglio. Using Beven's guts and a CZ large base pad they worked in my gun without touching the tubes.

good luck

[kneelingatlas]

I've been working on a compensated 9mm upper for my TS and since I don't really want to invest in another set of mags until I'm ready to rock I've been using my 40 mags with stock guts and CZC base pads which hold 23 1/2 rounds of 9mm and 20 1/2 rounds of 40. This would make me believe that with modified guts I should easily get 24+ and if I make a big stick out of 40 mags I should be able to get 30+. The only problem I've had with 9mm in 40 mags is maybe 10% of the time the las round in the mag pops straight up, something I feel could be fixed by tuning the feed lips.

I know CZ put the ribs on 9mm mags for a reason, but I haven't really see it. Does anyone have long term experience using 40 mags for 9mm? I can't be the first person to try this? Obviously I'm a little nervous to start experimenting with $50 tubes...

[flack jacket]

I've been working on a compensated 9mm upper for my TS and since I don't really want to invest in another set of mags until I'm ready to rock I've been using my 40 mags with stock guts and CZC base pads which hold 23 1/2 rounds of 9mm and 20 1/2 rounds of 40. This would make me believe that with modified guts I should easily get 24+ and if I make a big stick out of 40 mags I should be able to get 30+. The only problem I've had with 9mm in 40 mags is maybe 10% of the time the las round in the mag pops straight up, something I feel could be fixed by tuning the feed lips.

I know CZ put the ribs on 9mm mags for a reason, but I haven't really see it. Does anyone have long term experience using 40 mags for 9mm? I can't be the first person to try this? Obviously I'm a little nervous to start experimenting with $50 tubes...

I know it's an old thread. When I was still using my P9. I used the Small frame SP01 26rnd, Replaced factory with GE 9mm Spring and follower, machined out the Follower guide at bottom of mag = 28 . Super reliable.