CZ open 9mm

[TeamGE]

I am not sure how you could get 24 with the Grams kit,I could get 23 if I push it,but why slam it up against the ejector on a reload and it might not be reliable.22 rnds in mine feed everytime and thats what I am looking for.Whats worse having to reload in a stage because you have 22 or having a hicup with your mag in the middle of the stage because you got 24.Ed has taught me a lot shooting with him,and the biggest thing I have learned is make sure your equipment is reliable and works everytime you use it don't hung up on more when less will do the job perfectly.

Oh and thanks again Beven

I agree 100%, reliability is #1, round count comes second.

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

Limited Division legal mag length at 141.25mm,

9mm = 23 rounds (SP01 tube)

.40 = 21 rounds (Tactical Sport tube)

Open Division legal mag length at 171.25mm,

9mm = 29 rounds (SP01 & TS tubes)

Edited April 14, 2010 by TeamGE

[Bob Hostetter]

Beven, with the resurgence of interest in the CZ and small frame Tangfolio's it is time for you to start tuning magazines for them. Or at least teach someone else how to do them the right way.......

[TeamGE]

Beven, with the resurgence of interest in the CZ and small frame Tangfolio's it is time for you to start tuning magazines for them. Or at least teach someone else how to do them the right way.......

I hear you Bob,

I know we have talked about that, but I am just not ready for the pain,,,,,,,, yet.

[FLL1911]

Oh, FYI: Bevin Grams is making spring/follower kits for the 19rd CZ mags now FKC-11 is the part number you are wanting.

I have those. I can get 24 rounds with the CZ 19 rounds mag and the Pearce Grip basepad, but they are unreliable. I have tried almost everything I could think of to make it work. They are not reliable with the Tanfoglio mag either, but the 9mm Grams kit works flawless with the big stick made of a CZ-26 mag.

By the way, they are the standard Grams follower made for STI/SVI, roughly shorted to fit a standard 9mm mag.

Hello FFL1911,

From your description of the Grams Follower Kit you are trying to use in your CZ75 mags, you are not using the FKC-11. This new follower kit is designed closer to my Tanfoglio follower not the Grams STI/SV follower. At current production, the follower is marked "TC" in the bottom of the follower. You may be having problems because of this. But, I would also suspect that your 19 round mag tubes are not shaped right, compared to your big stick, since the big stick seems to be working fine (J-Hon touched on this issue in a previous post). I would also assume that you changed to a 13 coil spring for the big stick. I welcome any questions on this, just give me a call.

Hello Beven,

You are right, I am not using the new FKC-11 follower kit. I got those from ShooterConnection, and I believe they were initially designed for STI/SVI 9mm mags. Their appearance clearly showed a standard follower with the back cut (roughly I might say) to fit a smaller mag, but that was what were available by beginning of 2008, when I bought it, before the gun was built. I am not sure I have any problems with my CZ mags - they were factory mags, and I have 4 of them, plus one Tanfoglio mag, and I had experienced the problem in all of them - I made sure to rotate mags and spring and followers between them. I was using 11 coils spring with the CZ 19 rounds mags and 13 coils with the Tanfoglio and the big stick. I am not sure, but it also could be the cycle rate of the 9mm Major ammo (115 gr MG, 8.6 gr HS6). The CZ SP01 open is my first Open gun, and I started shooting 9 mm Minor with Winchester WB for about a 6 weeks before starting reloading 9mm Major, and I do not recall having any feeding problem with Grams followers with standard 9mm ammo.

I am glad to know that there is a kit for CZ, and I will give you a call during the week to try to sort out what is going on with my mags / Grams follower combination - I have been using Grams kit on my STI limited for years and they always proved 100% reliable to me, and it works on my 9mm big stick - so they MUST work with my other magazines.

Thanks,

Marco

[FLL1911]

I am not sure how you could get 24 with the Grams kit,I could get 23 if I push it,but why slam it up against the ejector on a reload and it might not be reliable.22 rnds in mine feed everytime and thats what I am looking for.Whats worse having to reload in a stage because you have 22 or having a hicup with your mag in the middle of the stage because you got 24.Ed has taught me a lot shooting with him,and the biggest thing I have learned is make sure your equipment is reliable and works everytime you use it don't get hung up on more when less will do the job perfectly.

Oh and thanks again Beven

Yeap! 24 rounds with Grams kit, and easily reloadable. To double check, today I got one of my magazines, replaced the guts and tried it again - it looks like the actual capacity is 24 1/2 rounds - it can be compressed back easily and would get a clean reload. Remember I am using Pearce Grip basepad which could be a little longer than the one you are using. The reliability issues I mentioned happened with 22 and 23 and 24 rounds on the mag.

Yes, 22 rounds are plenty enough for the vast majority of stages where a reload is needed, but in my opinion, if a magazine is reloadable with the maximum capacity, loading less rounds will not make it more reliable - my 2 cents.

[eerw]

23 or 24 in the mag is great when shooing minor limited. I actually won a stage with my 23rnd mag because I did not have to do a reload against the 22 rnd SV/STI 40 guys.

[TeamGE]

Oh, FYI: Bevin Grams is making spring/follower kits for the 19rd CZ mags now FKC-11 is the part number you are wanting.

I have those. I can get 24 rounds with the CZ 19 rounds mag and the Pearce Grip basepad, but they are unreliable. I have tried almost everything I could think of to make it work. They are not reliable with the Tanfoglio mag either, but the 9mm Grams kit works flawless with the big stick made of a CZ-26 mag.

By the way, they are the standard Grams follower made for STI/SVI, roughly shorted to fit a standard 9mm mag.

Hello FFL1911,

From your description of the Grams Follower Kit you are trying to use in your CZ75 mags, you are not using the FKC-11. This new follower kit is designed closer to my Tanfoglio follower not the Grams STI/SV follower. At current production, the follower is marked "TC" in the bottom of the follower. You may be having problems because of this. But, I would also suspect that your 19 round mag tubes are not shaped right, compared to your big stick, since the big stick seems to be working fine (J-Hon touched on this issue in a previous post). I would also assume that you changed to a 13 coil spring for the big stick. I welcome any questions on this, just give me a call.

Hello Beven,

You are right, I am not using the new FKC-11 follower kit. I got those from ShooterConnection, and I believe they were initially designed for STI/SVI 9mm mags. Their appearance clearly showed a standard follower with the back cut (roughly I might say) to fit a smaller mag, but that was what were available by beginning of 2008, when I bought it, before the gun was built. I am not sure I have any problems with my CZ mags - they were factory mags, and I have 4 of them, plus one Tanfoglio mag, and I had experienced the problem in all of them - I made sure to rotate mags and spring and followers between them. I was using 11 coils spring with the CZ 19 rounds mags and 13 coils with the Tanfoglio and the big stick. I am not sure, but it also could be the cycle rate of the 9mm Major ammo (115 gr MG, 8.6 gr HS6). The CZ SP01 open is my first Open gun, and I started shooting 9 mm Minor with Winchester WB for about a 6 weeks before starting reloading 9mm Major, and I do not recall having any feeding problem with Grams followers with standard 9mm ammo.

I am glad to know that there is a kit for CZ, and I will give you a call during the week to try to sort out what is going on with my mags / Grams follower combination - I have been using Grams kit on my STI limited for years and they always proved 100% reliable to me, and it works on my 9mm big stick - so they MUST work with my other magazines.

Thanks,

Marco

Ok Marco,

you bring new info to light that may point to your mag issues. (1) your short mags worked with minor pf loads, but not with major pf loads. Have you tried a stronger recoil spring to slow down the slide speed? Have you tried a longer mag spring in your short mags to see if you need more up feeding pressure with the faster slide speed? (2) Your finely (or should I say "roughly") described detail of my FKS9-11 Follower Kit is designed for a STI mag tube, with a spacer plate installed inside the tube, for the 9x19 cartridge. It is not designed to fit all 9mm mags in general. Using the right follower and spring length to match the operating conditions for your mag tube and base pad will make a reliable package.

I look forward to your call, Marco.

[TeamGE]

I am not sure how you could get 24 with the Grams kit,I could get 23 if I push it,but why slam it up against the ejector on a reload and it might not be reliable.22 rnds in mine feed everytime and thats what I am looking for.Whats worse having to reload in a stage because you have 22 or having a hicup with your mag in the middle of the stage because you got 24.Ed has taught me a lot shooting with him,and the biggest thing I have learned is make sure your equipment is reliable and works everytime you use it don't get hung up on more when less will do the job perfectly.

Oh and thanks again Beven

Yeap! 24 rounds with Grams kit, and easily reloadable. To double check, today I got one of my magazines, replaced the guts and tried it again - it looks like the actual capacity is 24 1/2 rounds - it can be compressed back easily and would get a clean reload. Remember I am using Pearce Grip basepad which could be a little longer than the one you are using. The reliability issues I mentioned happened with 22 and 23 and 24 rounds on the mag.

Yes, 22 rounds are plenty enough for the vast majority of stages where a reload is needed, but in my opinion, if a magazine is reloadable with the maximum capacity, loading less rounds will not make it more reliable - my 2 cents.

You bring more new info to light, Marco,

Your choice of base pad may make the mag length longer then a 11coil spring can provide feeding pressure for, since it is the last 3 rounds you are having trouble with. Try a longer mag spring. I know it may reduce capacity, but since you say you have 24.5 rounds of room, you can get 12 coils in there and still have room for 24. I suspect you have a mag length over 145mm.

[Big Dog Howie]

I am not sure how you could get 24 with the Grams kit,I could get 23 if I push it,but why slam it up against the ejector on a reload and it might not be reliable.22 rnds in mine feed everytime and thats what I am looking for.Whats worse having to reload in a stage because you have 22 or having a hicup with your mag in the middle of the stage because you got 24.Ed has taught me a lot shooting with him,and the biggest thing I have learned is make sure your equipment is reliable and works everytime you use it don't get hung up on more when less will do the job perfectly.

Oh and thanks again Beven

Yeap! 24 rounds with Grams kit, and easily reloadable. To double check, today I got one of my magazines, replaced the guts and tried it again - it looks like the actual capacity is 24 1/2 rounds - it can be compressed back easily and would get a clean reload. Remember I am using Pearce Grip basepad which could be a little longer than the one you are using. The reliability issues I mentioned happened with 22 and 23 and 24 rounds on the mag.

Yes, 22 rounds are plenty enough for the vast majority of stages where a reload is needed, but in my opinion, if a magazine is reloadable with the maximum capacity, loading less rounds will not make it more reliable - my 2 cents.

Yes probably the pearce pads will hold more,but 2 things/one they don't seem reliable according to what you have said,and two are they longer than 140mm.

I think 22 is enough if you are shooting Limited,if you shoot NRG Jojo's stages are never less than 26 rnds so unless you are shooting open you are going to have to reload.Of course there is steel and I hate steel so a few extra rnds doe's not hurt.Any way I am no expert,and this is just my 2 cents.

[eerw]

the pearce pads on the 16rnd mags meet 140mm as do the SP01 mags with the mecgar +2 pad ( got to trim the back just slightly)

22rnd pretty easy. the SP01 with Mecgar +2 pad is a better fit to the guage and can get 23 with big mods to the followers. really looking forward to trying Beven's stuff for the CZ

Edited April 14, 2010 by eerw

[shooterbenedetto]

Stuart, thanks for posting. I noticed that you include

the base plate! including the base plate I believe

makes the mag more reliable, spring is compressed correctly. Cant wait to play

around with bevens stuff also. 22rds is good

enough for me as long as they are reliable!

23-24 would realy be awsome especially for

medium stages..

Edited April 14, 2010 by shooterbenedetto

[FLL1911]

I gave a call to Beven today as mentioned - It was a pleasure to talk to him! Among other things, he explained to me how the transition from double stack to single stack works inside the magazine and how important is the magazine shape close to the top to handle it properly. I will follow Beven’s suggestion posted earlier, but more likely my mags need to be tuned, and this service is planned be available from Grams Engineering in the near future.

Thanks Beven,

Marco

[J-Hon]

Whoa... Bevin is really thinking about tuning CZ mags now? Exciting prospect.

Looks like things are really shaping up to make open CZ's a serious proposition.

[FLL1911]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

Edited April 15, 2010 by FLL1911

[Big Dog Howie]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

How did you shorten the CZ 26 mags,I found a source for them.

Edited April 15, 2010 by Big Dog Howie

[TeamGE]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

Marco,

you have correctly identified the taper differences that show at the back of the mag tubes. You are however missing the most important difference. Looking at the side of the mag tube, there is a "control rib", or dent (if you want to call it that) that is suppose to start lower in the tube, then the taper at the back of the tube. Look at the differential between the starting point of the back taper and the control rib on the same tube. Your best running mag (far right in your picture) has the control rib starting far below the taper at the back of the tube. This differential is why the mag has a better "nose up" position of the cartridge, thus feeds better. The far left mag has the worst differential and would explain its poor "nose down" feeding problems. A factory follower (long legs and a wedge nose up shape) tries to hide this design problem, to force the column of ammo in a nose up position, but this is very difficult to do in the double stack area of the tube. The wedge shape drags the inside front and back of the tube, and adding more spring pressure causes the friction to be even worse, so it is counter productive. I highly recommend lubricating the inside of the tube to help with the friction problems of this design. As a side note, the long legs and wedge shape take up room, so you loose round count.

[Big Dog Howie]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

How did you shorten the CZ 26 mags,I found a source for them.

Actually I thought I had a source but turned out to be the wrong mags.

[eerw]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

Marco,

you have correctly identified the taper differences that show at the back of the mag tubes. You are however missing the most important difference. Looking at the side of the mag tube, there is a "control rib", or dent (if you want to call it that) that is suppose to start lower in the tube, then the taper at the back of the tube. Look at the differential between the starting point of the back taper and the control rib on the same tube. Your best running mag (far right in your picture) has the control rib starting far below the taper at the back of the tube. This differential is why the mag has a better "nose up" position of the cartridge, thus feeds better. The far left mag has the worst differential and would explain its poor "nose down" feeding problems. A factory follower (long legs and a wedge nose up shape) tries to hide this design problem, to force the column of ammo in a nose up position, but this is very difficult to do in the double stack area of the tube. The wedge shape drags the inside front and back of the tube, and adding more spring pressure causes the friction to be even worse, so it is counter productive. I highly recommend lubricating the inside of the tube to help with the friction problems of this design. As a side note, the long legs and wedge shape take up room, so you loose round count.

Beven..if the control rib starts lower does that start the stack narrowing sooner. and is that what lessens the nose dipping? How much does the length of the feed lip contribute to reliability as doesn't that determine the time of which the round releases and its angle entering the feedramp?

[TeamGE]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

Marco,

you have correctly identified the taper differences that show at the back of the mag tubes. You are however missing the most important difference. Looking at the side of the mag tube, there is a "control rib", or dent (if you want to call it that) that is suppose to start lower in the tube, then the taper at the back of the tube. Look at the differential between the starting point of the back taper and the control rib on the same tube. Your best running mag (far right in your picture) has the control rib starting far below the taper at the back of the tube. This differential is why the mag has a better "nose up" position of the cartridge, thus feeds better. The far left mag has the worst differential and would explain its poor "nose down" feeding problems. A factory follower (long legs and a wedge nose up shape) tries to hide this design problem, to force the column of ammo in a nose up position, but this is very difficult to do in the double stack area of the tube. The wedge shape drags the inside front and back of the tube, and adding more spring pressure causes the friction to be even worse, so it is counter productive. I highly recommend lubricating the inside of the tube to help with the friction problems of this design. As a side note, the long legs and wedge shape take up room, so you loose round count.

Beven..if the control rib starts lower does that start the stack narrowing sooner. and is that what lessens the nose dipping? How much does the length of the feed lip contribute to reliability as doesn't that determine the time of which the round releases and its angle entering the feed ramp?

Correct, starting the bullet tips to narrow first, before the rim of the cartridge, creates "nose up" pressure at the feed lips. Moving the starting point of the control rib, lower in the tube, and/or making the rib deeper, will create more nose up pressure, up to a point were you will loose round count, but at least the mag runs right. This is another example of "capacity verses reliability".

A "nose down" or "nose dive" condition is the problem of the bullet nose hitting the feed ramp very low, and not wanting to travel up to the chamber. A nose dive problem is caused by not having enough support under the cartridge. This support comes from the cartridge underneath the top round or the follower itself. During the feeding process, the bottom corner of the breech face pushes on a very small part of the rim, and it is the top of the exposed rim to boot, which has a natural tendency to push the tip of the bullet down, as it is being pushed forward to the feed ramp. A slow running mag, or slide speed that it too fast for the mag to keep up, will cause a nose dive FTF because the breech face picked up even less the rim to push on. "Feed lip width" controls how high the cartridge sits in front of the breech face for feeding, and "feed lip length" determines when the rim of the cartridge is released, after the bullet has already moved up the feed ramp and entered the chamber. This angle you refer to would then be "chamber entry angle" and not feed ramp angle. Chamber entry angle is important for fixing problems with the rim of the cartridge slipping under the extractor during the chambering and locking into battery process.

Edited April 15, 2010 by TeamGE

[flack jacket]

Beven, with the resurgence of interest in the CZ and small frame Tangfolio's it is time for you to start tuning magazines for them. Or at least teach someone else how to do them the right way.......

Good idea Bob!

Edrick <-------------- Small Frame P9 shooter

[FLL1911]

From the conversation with Beven today regarding how the round tendency to keep the nose down is related to how the magazine taper handles the transition from double stack to single stack, I put my magazines side by side, and noticed that they have different taper transition– the Tanfoglio has the longest taper, the CZ a little shorter than the Tanfoglio, and the big stick the shortest of all.

Coincidence or not, the tendency to nose diving is greater with the Tanfoglio, still occur with CZ mag, but does not occur with the big stick. If I change to a follower that has legs, forcing the round nose up, the FTF nose dive does not occur in any of my mags. Not my area of expertise, but the taper length / angle seems to be a close relationship with the FTF described earlier– correct me if I am wrong.

I put some masking tape on the mags, right on where the taper begins and took some pictures:CZ SP01 Open Magazines

How did you shorten the CZ 26 mags,I found a source for them.

Venry did it. You can contact him directly at Radical Precision. I do not know the details.

If you would like to share the CZ26 mag source, I would appreciated it. You can message me if you want.

Marco

[FLL1911]

Beven, thank you for the comments,

Marco

[kneelingatlas]

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.

Edited November 12, 2012 by kneelingatlas

[Jon Merricks]

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.

Beven last posted in this thread about two and a half years ago so I'm not sure you will get a reply.

[kneelingatlas]

Good point, momentary insanity I guess.