The Original CZ Forum
CZ PISTOL CLUBS => CZ75, 75b, 75 SAO inc the Transitional => Topic started by: Walkure on April 02, 2009, 10:24:20 PM
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This is really more feedback than a question, but since it's directed at CZ gunsmiths & reps, I thought it might fit in best here. I also figured it best to post on the forum instead of sending an email, as this will allow for more open discussion and for any others with similar experiences to come forward.
The problem:
Aftermarket Mec-Gar 17-round and 19-round magazines will contact the Omega trigger bar spring when fully inserted. If seated with a good amount of force, the magazine can cause the trigger bar spring to dislodge from the frame and become a loose part, rendering the pistol useless. The factory mags that shipped with my 75B Omega do not contact the spring, but come extremely close, so this could possibly also be an issue with any slightly-out-of-spec factory magazines.
My solution:
Create a relief in the aftermarket magazines to eliminate contact with the spring.
Proposed "better" solution:
Extend the length of the trigger bar spring which sits in the frame. I would say that doubling the length of that leg and appropriately deepening the hole in the frame would likely prevent the spring from being pushed out of place in any situation.
Background/detail:
I have been shooting CZs off and on for about five years now - since my father bought a CZ75B when I was in college. Recently, I purchased one of the new CZ75Bs with the Omega trigger system. I have been very pleased with the pistol; I could not find any significant fault with it until I discovered the aforementioned issue when practicing reload drills this evening. While performing these drills, I noticed that the mags were starting to fail to drop free - not just one, but nearly all of them were sticking, requiring manual removal. After checking all of the mags again, they started to drop free again, but the trigger just stopped working - it clearly wasn't engaging the sear at all. I detail stripped the pistol to find that the trigger bar spring was missing. Upon returning to the spot where I was practicing my reloading drills, I discovered the spring on the floor.
After much investigation, I finally found that the problem lie with the profile of the aftermarket Mec-Gar mags I was using. The taper on these mags (from double-to-single-stack) begins slightly higher on the body than the factory magazines. This, in turn, causes the mag to contact the trigger bar spring. If the magazine is seated very glenty, no adverse effects could be seen. However, if the magazine was seated forcefully - as would be done in any practical shooting sport or in a defensive shooting course - it would often cause the short leg of the spring seated in the frame to be pushed up just out of its housing, causing the entire trigger bar spring to become loose betwen the frame and magazine. If the magazine was removed, the spring would generally fall out with it.
By removing everything from the frame except for the magazine catch assembly and the trigger bar spring, I was able to see the actual contact of the Mec-Gar magazine against the spring. I also noted that while the factory magazine does not contact the spring, the clearance between the magazine and the bottom edge of the spring is very, very small. A slightly out-of-spec magazine with a marginally larger width at this specific point would cause the same behavior as the Mec-Gar magazines, while still functioning normally with the pistol in every other sense. Additionally, I am curious about the factory SP-01 magazines; as I do not have any myself, I cannot perform any comparisons or tests. However, if their profile is similar to the Mec-Gar profile, with the higher/wider taper - something I would not be surprised about, given their higher capacity over standard CZ75 magazines - then they would also cause this issue.
Having finally determined the cause of the problem, I decided to go about fixing it. While my first thought was that the spring should be better retained by the frame to prevent this altogether, alas, I have no way to produce a new spring with a longer leg, nor do I currently have a small enough drill bit suitable for deepening the hole in the hardened steel frame. So I decided to modify the aftermarket mags instead. I selected one of the 17 round magazines and created a small relief, using both my dremel and some needle files. This mag no longer contacts the trigger bar spring - and neither I have been able to dislodge the spring by seating this mag forcefully, despite many repeated attempts at doing just that (like I had been able to do before creating the relief).
I am rather surprised that I am the first to report this issue (AFAIK), as Mec-Gar is a particularly popular and well-thought-of aftermarket magazine manufacturer, especially for CZs. I doubt I will be the last to experience this, however, as the short "frame leg" of the trigger bar spring in the Omega system seems to be an inhernet design flaw - albeit one that could easily have been overlooked during actual development, due to the somewhat obscure way (at least from a design point) in which this came into play.
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both are relatively new introduction in the past few months..MecGar changed the mag design late last year..and the first Omega weren't seen till earlier this year..so the combination of the two hasn't really been prevelant.
really appreciate your observation of the combination of the two together.
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Nice work.
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Thanks for posting this info. It saves me from trying my Omega with MecGar Magazines and being frustrated thinking it was just my pistol.
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from the description it is only the new style mecgar AFC mags..not the older 16rnd mags..
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from the description it is only the new style mecgar AFC mags..not the older 16rnd mags..
Correct, at least in that I can only verify the problem exists with the AFC 17- and 19-round magazines. If the 16-round magazines directly match factory specs, this shouldn't be an issue - unless the tapered region is slightly wider or otherwise out-of-spec, like I mentioned.
(http://img153.imageshack.us/img153/1513/czvsmg.jpg)
This illustrates the difference in where the taper occurs on the newer MG vs factory CZ magazines.
(http://img227.imageshack.us/img227/3308/mgmod.jpg)
This illustrates the modification I have made to eliminate the problem on my MG mags - basically, creating a releived region above the taper line and forward of the center depression. (Only on the right side, of course, since the Omega system uses a single-sided trigger bar.)
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Thanks for the info Walkure. I thought I had a bad trigger bar spring and sent my 75B Omega back to CZ for repair. I should have sent my new Mec-Gar mag to CZ with the gun so they could see the problem. I will have to use your fix. Thanks.
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Update:
Shot the Omega tonight in a USPSA match (Limited, minor) using the mags with the mods - two trigger bar spring failures when using the extended MG mags. The first was a complete failure, whereby the spring came completely loose and ended up on the ground. On the second, the spring remained in the gun, but was barely kept there and was thus still causing issues.
I used only the factory 16-rounders for the last COF, and had zero problems in that run.
I'm beginning to think that without some kind of actual fix involving the spring itself, I'm just going to give up on running anything but standard 16-round mags with my B-?.
Also, does anyone have any SP-01 mags that they could compare to either the standard 16's or the AFC 17s/19s? Just wondering if they have the same taper as the higher-cap Mecgars (and thus could cause the same problem)...
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Also, does anyone have any SP-01 mags that they could compare to either the standard 16's or the AFC 17s/19s? Just wondering if they have the same taper as the higher-cap Mecgars (and thus could cause the same problem)...
Sorry to hear about your troubles. I gave up on the P07 in my USPSA match last night and stuck with my 97. Everything was working fine, but the reset was killing me.
Anyways, the SP01 mags have the same taper as the old style Mec-Gars. They should work ok for your application.
Good luck - I'm sure we'll get these bugs worked out sooner or later.
;)
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Update: STILL happening. Now using only the factory mags. Had it back at the range today... something clearly wasn't right with the trigger again after only ~30 rounds. The spring appeared to be securely in place, but when I dropped the slide before putting it away (to investigate later), the spring fell right out.
It went like this:
- Huh, trigger is funky again.
(DROP MAG)
(FLIP PISTOL OVER)
- Nope, looks like the spring is still in there. Guess I'll have to take a closer look later.
(WALK OVER TO CASE)
(DROP SLIDE)
(SPRING FALLS OUT)
- F@%$, not again!
Again, this was using only the factory 16-round mags.
Guess I have no choice but to send it in to CZ.
I'm leaving on vacation in the middle of next week, so I'll wait until I'm back to call them up and see if they have anything else to say. (Since if I do have to ship it back, I won't be able to get around to it until I'm back from vacation anyway.)
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Walkure,
This must be very frustrating for you. I hope CZ-USA can fix this problem. Please keep us informed as to the hopeful resolution of your problem.
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I have the same problem. I'm about to sent it back to CZ. What did CZ do when they fixed it?
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http://www.ar15.com/forums/topic.html?b=5&f=37&t=73997&page=3 (http://www.ar15.com/forums/topic.html?b=5&f=37&t=73997&page=3)
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Stuart:
Thanks, I guess that explains the ending to the whole story.
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I have the same problem. I'm about to sent it back to CZ. What did CZ do when they fixed it?
It ended up being replaced with a standard-trigger 75B (at my request over a replacement Omega). They said that they had fixed whatever the underlying cause was, but that then the trigger bar spring broke off and became hopelessly lodged in the frame, necessitating a replacement.
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I can vouch to have this problem. Unfortunately it happened to me when I was doing my certification for carry.
Going to either trade my magazines with a friend who doesn't have this trigger or something.
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it seems like the previous owner of mine had this problem, but the two factory and one mec-gar 16 mags I have work fine, I've had no problem with it.
I can think of ways to get around this but they involve re inventing the spring that pushes up on the transfer bar. I'll probably keep shooting it until it gives me a problem
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Going to either trade my magazines with a friend who doesn't have this trigger or something.
Contrary to my very early thoughts, the problem is unrelated to magazines.
Other posters (here and elsewhere) who have had trigger bar spring problems have reported that CZ-USA now openly acknowledge this issue with B-Omega pistols and will perform some type of corrective action (presumably, that would be staking the spring in the frame).
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Hi all.
I recently purchased a 75b from Cabelas. (Have also had a P-01). Did it as a phone order and when I picked it up I found that it was an '08 with an Omega trigger system. I was okay with that, but having followed this thread with interest, when I got home I put a bit of pressure on the trigger bar spring from underneath with my finger and it immediately slipped out of its hole in the frame.
I called CZUSA and spoke briefly with one of their gunsmiths. I described the problem and asked if, being a reasonably handy guy, I could effect a repair myself without having to send it in to them. They said yes. I was told three things: 1) if the spring protrudes as much as 1/4 " or more from the hole before its first bend (assuming that it is well seated in the hole to begin with) filing off a bit (say 1/16") from the short leg that sits in the hole will help with the general function of the spring (not sure why). 2) As was mentioned in an earlier post, they mentioned that staking the spring by using a sharp punch (I used an ice pick) directly next to the spring's entry point into the frame should anchor it. When I mentioned that I had thought to use a drop of epoxy or lock-tite, the smith mentioned that, 3) they often use a drop of super glue in addition to the staking, particularly on the poly frames.
Bottom line: I used a very small amount of epoxy, dipped the short leg of the spring in that, pushed it into position in the hole, and then staked it. It now seems quite solidly in place. :D
Thanks much for the heads up about this issue!
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mine was loosely in the hole and held up for about 400 rounds with zero problem. if I would have kept it I probably would have staked it in somehow, but sold it because I needed the money. I wouldn't have a problem owning another omega as long as you only had 16 round mags, but odds are I will buy another plain 75b in the future when my wallet allows it.