TeamGE

Put a Grams 4mm base pad on it, and check the AOL in a Mag Gauge. If it does not fit, remove material from the feed lips till it does, then readjust the feed lips back to the right width. If it does not hold 29 rounds at that point, then the mag tube needs to be reshaped/tuned.

I agree with you and Beven however in my case it was once fired (I cut the crimp off) shiney new LC. I adjust my die to no more then .003 pushback from fired cases and thousands of rounds before and after with the same dimensions with no problems. I also have a bucket of a few thousand rounds of practice brass that I have loaded close to the same specs 8-12 times. All of the above comments are true if your having one split here and there I just think that somtimes its just a bad piece of brass and you move on .. I agree, sometimes it is just bad brass. I wonder if maybe the brass you have could be a little too hard, either work hardened or from the factory, and doing some annealing would save them. We usually don't anneal that far down the case wall, but one could certainly do that.

Shooting the much higher BC 107g 6mm bullets, compared to the same weight 6.5mm bullets makes a lot of sense to me. I think the 6mmAR (or one of its other fire formed wildcat forms) is a good call. I have already started my build. Should be a fun project.

I have had this type of separation before, from used brass that I had picked up for outside sources. When cases are shot, they stretch. This is why we have to case trim. If they are resized shorter then they need to be, or shot in longer then normal chambers, they stretch even more. The brass we trim off has to come from somewhere. It comes from the case walls. The case walls are thicker at the bottom and taper to thinner wall thickness right past half way to the shoulder. The thinner wall thickness from that point, to the shoulder, is where most of the shretching is going to happen, and thus the walls get thinner every time you shot it. When the case has had enough, it will separate in a perfect line like your picture. In stretched cases that are close to separating, if one where to inspect the inside of the case with a bore scope, you can see the ring forming where the separation is going to happen. Not much you can do to avoid this with used brass (besides good inspection), unless you reload only the brass from your chamber, and minimize your headspacing.

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.

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.

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.

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.

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

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)

Part #FKC-11 and FKC-13 will fit mags related to both the "small frame" CZ75/SP01 and "large frame" Tactical Sport" type guns. The 11coil kit is designed for mags that are up to 145mm in length, and the 13 coil kit is for longer mags up to the 171.25mm mark ("length of mag" means tube and base pad combined). These kits will not work in mags that have "dents" or "protrusion" to the inside of the tube, that narrow the inside of the tube smaller then a double stack of ammo. With the large variety of mags available for the CZ line of guns, both factory and aftermarket, it is impossible for me to say specifically which tubes will work properly or if there is a specific issue with one type. I have designed these kits to work with the factory mag tubes I have on hand. As time goes on, I collect more mag tubes, and try to keep up with the changes that materialize. I find that even factory tubes change from manufacturing run to run, and can have a huge influence on the reliability. If someone is using a tube that seem to have an issue, I welcome phone calls to help figure them out.

Sounds to me more like an extractor/ejector problem. Try one round with no mag in the receiver. It could be that a mag with rounds in it, helps the ejection process, and then when it is empty, the last round does not get this help. The bolt could be short stroking, this would explain the need for a stronger load to eject on an empty mag. Just my .02 worth of thought.

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.

The bolt handle/side charging handle thing has been discussed here . I personally like it, and have been using it.

I have one, custom made to my specs, designed to chamber reloaded ammo, made by standard Dillon dies, with lead bullets. Call or email me direct for more details.

That's some good planning there Nick!

Beautiful job on the barrel but I agree, those are ports, welcome to Open. At least you'll score major. Doug I have always understood Tactical-iron and Tactical-scope allow comps, which have chambers and ports. As long as the rifling stops at the first port, any chambers or ports after that is considered a comp in design. A comp does not have to be screwed or clamped on. I see no reason for a bump to Open division as long as it meets the diameter and length dimensions.

The rules I read say maximum 1" diameter x 3" long, starting at the crown of the rifling, to the front (muzzle end) of the comp, or in your case what use to be the crown. If you are in that dimension, you are good to go.

And while we are at it, left hand bolt handle on my Benelli M1S90.

Bolt handles on an AR10.

I have been building bolt handle AR15 and AR10 uppers and competing with them in multi gun competitions for over 3 years now. I find the natural ergonomics of use is very easy to get use too. Is this idea good for the battle field? I would say not, for the simple fact that dirt and debris can get into the open slots and breach. I prefer bolt handles on both sides, with the left side being used 95% of the time. The right side is mostly used when the gun is staged in a position that requires charging the gun in some weird position. The one hidden purpose of the right handle is that it works as a brass defector. If one where to only want one handle, the left side would be the one to have. Right side is usually good for bench rest stuff. Here are some pics of my work for the AR15.

Yes, a new "Follower Kit" (part# FKC-11, includes Grams Format Follower and 11 coil spring) designed for the CZ 75 and CZ Tactical Sport mags with slide lock function retained. The 11 coil spring is designed to work in mags with extended base pads installed, and measure up to 145mm long. A 13 coil spring is available for 170mm mags. The FKS9 follower will work in the CZ mags, but is slightly too narrow and has a tendency to not stop at the feed lips when the mag is empty. This follower is intended to be used in STI mag tube when a spacer plate is used for 9x19.

hm, i'm going to have to try that. where is the follower kit available? Call me direct at the number below. It is not on my website yet. Angus should have them in the near future.

21, in the tube, reloadable, with Angus pad and Grams FKC-11 Follower Kit.

My question is "If a STI type mag is used in the Caspian frame, how does it fit into a hole that is too small for the mag?" Is the frame some how widened by means of cutting and welding material to it to make it wider? I know that my Caspian high cap frame is not wide enough.