Can a 10 round 9mm magazine be altered to take 13 rounds?

[theman2001]

I was wondered if the bottom of the magazine can be altered to accept 13 rounds?  I remember doing this to a Ruger 9mm and was able to go from 15 to 17 rounds.

Has anyone else tried this?

[Old Coastie]

When I first got my 9mm CZ100 I took a look at the 10 rnd. magazines and quickly decided they could not be altered to hold over 10 rounds. If yours are like mine were, they are laser cut all the way around except in the recessed sections. You would have to weld up the cuts, grind the welds smooth both inside and out and then polish the grind marks. Way too much work.

Why not just buy 13 round magazines from CZ-USA. Not real cheap, but they work.

Good shooting,

Mike

[theman2001]

That does sound like to much work.

In the Ruger I just ground down the bottom of the follower and stretched the spring.

Thanks

[lee n field]

Quote:Why not just buy 13 round magazines from CZ-USA. Not real cheap, but they work.

Or buy magazine tubes from CZ.

[Old Coastie]

The reason I suggested buying complete magazines is that from time to time, CZ changes the manufacturer of their magazines. It is possible that just the new tubes will not work properly with the rest of the old parts. Besides, if you have a problem with a CZ mag, they will take care of it. Don't know what they would do if your mag did not work and they found out it was a frankenzine.

Good shooting,

Mike

[Walt-Sherrill]

Screwing with 10-round mags trying to make them hold more is an exercize in futility.  Just buy some new mags.  

For the CZ-100, there aren't that many options.  But buying the .40 CZ-100 mags from Pro-Mag MIGHT be a good compromise.  (The .40 Pro-mag used in a regular CZ holds 13-14 rounds of 9mm.)

[theman2001]

"For the CZ-100, there aren't that many options. But buying the .40 CZ-100 mags from Pro-Mag MIGHT be a good compromise. (The .40 Pro-mag used in a regular CZ holds 13-14 rounds of 9mm.) "

I did not know that you can do that.  

That sounds like the easiest way to get more rounds.

[xaztec]

Why do the 9mm mags on CZ's site say 13 rounds but the mags on everyone else's site says 12 rounds?  The retailers say the 12 rounders are CZ manufactured mags.  Does CZ only give the retailers 12 round mags?

[dleong]

Quote:For the CZ-100, there aren't that many options. But buying the .40 CZ-100 mags from Pro-Mag MIGHT be a good compromise. (The .40 Pro-mag used in a regular CZ holds 13-14 rounds of 9mm.)

That's a nice bonus, to be able to use the .40 ProMag magazine to hold 9mm cartridges.

The factory magazines supplied with the .40 CZ pistols have feed lips that are just narrow enough to retain a 40 S&W cartridge. They won't retain a 9mm cartridge.

[Old Coastie]

I tried using a couple of Pro-Mags I bought for my 40 S&W CZ100 in my 9mm CZ100. The 9mm rounds just shot out of the top of the 40 mag. Maybe mine were different, because I know it works with Pro-Mag 40 S&W mags for the compact models. It might be worth a try. They may have changed the spacing of the mag lips in the last few years.

Good luck

[Walt-Sherrill]

If you want to try it, narrowing the mag lip gap a hair might make the .40 mags work.  ( In the Pro-Mags for the 75B gun, the gap is very similar.)

Narrowing the gap will probably be easier said than done, but you cna use the point of the bullet, right above where the case starts, as your yardstick.  Get it close to that width, and it'll probably work.

Some of these mags have very BRITTLE feed lips, so doing it may cause a break.  (I've not tried it with CZ mags, so am not sure what will happen.)

[xaztec]

I don't have any 12 round mags yet but I see the 10 round mag's spring has the same size winding its entire length.  I believe the springs on the newer hi-cap mags, at least with the full size gun mags, have windings that taper off as it gets closer to the top so that as it compresses, it stacks inside itself instead of on top of itself so it creates more room.  You could probably find a new style mag spring and try it.  You may still have to shave some off the bottom of the follower.  

If you're looking for higher capacity and don't care how it looks, any CZ75B mag, including compacts, will function in the CZ100.  They just hang out the bottom.  I was just up at the range shooting with my 26 rounder.  That one sticks out way way below the handle.

[Walt-Sherrill]

The springs for the fullsize guns are the same in 10- and 15- and 16-round mags.

I don't know about the CZ-100 mags, but I'll be really surprised if the springs are different.

I could NEVER get a standard CZ-75 mag to work in a CZ-100.  If you've done that, you've done something nobody else has been able to do -- and you'll probably get messages asking for tips.  (The mag release notches were quite different in mine.)

[xaztec]

Really?  That's odd.  I just got this gun.  This was the first time I shot it and I only have one 10 round mag with it so I just grabbed the 75b mags for the hell of it.  The factory mags I have were 15 rounders from my 75b military contract ("96").  I also had some aftermarket 15 round mags that I bought for the 75b like 8 years ago.  I have no idea who made them but they all worked in my CZ100...which is kind of odd because some of them didn't work that great in my CZ75b.  Maybe the military contract pistols had different mags?  These are old ones too and I understand CZ changes their OEM's from time to time so maybe they're slightly different now?  The "stepped" springs I was looking at were from my friend's Berretta MecGar mags but he said his 19 round SP-01 mags had the same kind of spring.  All my CZ 15 round mags have the regular springs though.  My CZ100 is the 9mm version by the way.  I should also note that I did not actually test the CZ75 compact mag for function, I just stuck it in to see if it would fit and it did.  It belonged to a guy at the range.  I'll go up there again this week and see if I can try his mag.  As for the 26 round mag, I tried it once with about 10 rounds in it.  It kept slipping but i figured I was pushing the mag release button by mistake...which, at first, I was.  I just tried cycling some rounds through it and I see it doesn't completely lock into place.  It will load the first round but then slips down and misses the next round so I have to give it another little tap.  I compared the mags and I see the mag catch slot is shorter than the other mags I have.  I think if I cut the slot a little longer it would lock and should still work in the 75b.  I'll have to try that too.

[xaztec]

Just got a Pro-mag CZ100 .40 mag and it holds 13 rounds of 9mm.  Seems to function ok just racking the slide with dummy rounds.