CZ Shadow mag tuning

Hi Guys

Does someone has any tricks to make my mags more reliable ?

I adjusted the lips and cleaned them but have lots of FTF/FTE on 2 of my mags, the others are working well but when I look at them I cannot see any difference between the working ones and the bad ones, they're all about 1½ year old/2k rounds each

the springs look the same tension of all of them (I don't mix parts from one to another)

thanks

Snowboy

Adjust your mag lips to .380 inches to keep the bullets from riding too high in the magazines.

This is a great site for Tango CZ info.
http://www.tanfo11.com/
 
This is a weird thread.

I have never had a problem with a CZ that I could blame on a mag!

Just lucky I guess.

John

What mags do you have? Are the full length steel ones pinned to 10 rounds or ones that can only hold 10 rounds because of the plastic bottom filler? Also, do you drop them a lot to the concrete?
 
Well, I have to sort of agree. So far my 5 mags have been 99.9% to 100% trouble free. Any issues I've had were due to leaving the gun for too long between cleanings and some cleaning had it back to good as new.

Thanks to a good example I've sinced stamped numbers on my mags and will be tracking any future issues to follow this more closely.

Snowboy, when you're tuning your mags it's not something you can do by eye unless you've got really sharp eyes and an even better judgement of really small distances. I'd suggest you get a cheap set of calipers and use them for measuring the distance between the lips and for the round protrusion height from the rim to the shoulder of the back of the mag opening. These numbers should be noted down so you can easily compare them later on. Differences of just a few thou will make all the difference and there's just no way to actually see this sort of thing without a set of calipers to show you an accurate measurement. "looks about right..." seldom is unless you've got years of experience to back up such a judgement.

Digital calipers are cheap these days but I'd suggest pay a couple of bucks more for a dial caliper. The darn digital ones always seem to have a dead battery when I go to use them. Meanwhile the dial ones work all the time, every time and are easy to use and read. The vernier calipers are even cheaper but good luck reading them if your addition skills are sketchy and your eyesight at all less than eagle like.... :D
 
Thanks BC but when I had the problem I measured them with my caliper without any difference between the good and the bad ones and, since I started this thread (feb 21th) I followed your suggestion and found that the problem of the faulty mags was that the lips were almost as sharp as a knife... they must have been sharpen when they fall on the ground and since a use a Uplula I didn't noticed . Just did a little touch with a dremel with cotton & Flitz to round them and had no problem since that.
 
What mags do you have? Are the full length steel ones pinned to 10 rounds or ones that can only hold 10 rounds because of the plastic bottom filler? Also, do you drop them a lot to the concrete?

I have the stock mags that come with the gun. Plastic/steel.

They have all hit the concrete now and then but I try to avoid it when I can. If I am shooting on concrete I try to put a piece of carpet down.

We don't normally shoot indoors so hard floors are usually not a big issue.

John
 
Aha!

Thanks BC but when I had the problem I measured them with my caliper without any difference between the good and the bad ones and, since I started this thread (feb 21th) I followed your suggestion and found that the problem of the faulty mags was that the lips were almost as sharp as a knife... they must have been sharpen when they fall on the ground and since a use a Uplula I didn't noticed . Just did a little touch with a dremel with cotton & Flitz to round them and had no problem since that.

Good to know :)

John
 
That would explain it. We have lots of indoor matches during winter time and addition to bi-weekly club matches. I lost count how many times my mags fall to the concrete floor...

I have the stock mags that come with the gun. Plastic/steel.

They have all hit the concrete now and then but I try to avoid it when I can. If I am shooting on concrete I try to put a piece of carpet down.

We don't normally shoot indoors so hard floors are usually not a big issue.

John
 
Polishing the lips occasionally likely isn't a bad idea. I tweaked a mag for a cheap .22 semi the other day that had been causing me no end of headaches. I could actually feel a casing being pulled through the rim lift "V" in the lips cutting into the brass. A minor tweak to narrow the lips and some smoothening and polishing and now the gun is shooting like a champ. So yeah, likely it's not a bad thing to just polish the lips every few thousand rounds to ensure that there's no sharp edges or burrs that are cutting into the brass and slowing things down or shifting the drag on the cartridge to one that wants to lift the nose.
 
Little mag tuning/testing trick:
Obviously check your dimensions and adjust accordingly.
Load mag to full, the with your thumb, just start the top round forward to maybe 1/8 inch (just enough to take it out of the fully seated position). Now grab the nose of the bullet between your index finger and thumb and pull it slowly forward and slightly upward, trying to roughly mimic the path it would take when being pushed by the slide. As you pull it out, note how the round drags (or doesn't) on the feed lips and on the round beneath. The round beneath shouldn't be a problem unless the case is bulged. If you feel drag in the pull, look at smoothing out the feed lips. A sharp edge or burr is common in newly minted mags.

Now repeat this and pull the next round out quickly,snapping it out FAST. Note how the round beneath pops up and presents. It should come up in the proper feeding presentation. If it doesn't, look at follower, feed lips and spring (see below).

FWIW: I polish my feed lips with either a craytex drum or 600 grit water paper. You should only have to do this once. I check all feed lips for spread every time I clean the gun, and clean the mags and followers with a silicon impregnated cloth.

Check springs for compression and kinking (they can tend to bend over backwards after a while) and check followers for burrs and build-up of grime. Follower angle in an empty mag should be the same as the feed lips, and the springs should have plenty of lift or fast cycling guns like CZ's with overrun them and start nose diving or trapping brass on ejection.

It's a good idea to number your mags so that if something goes wrong you can isolate it until you have a chance to deal with it. You can go so far as to number your followers as well if you want to eliminate all variables....

hope this helps

R
 
11# recoil spring is good enough for +10% mag springs. I used those +10s at a match last Sun and had zero problems while I'd have an ocasional stovepipe with factory mag springs. Well, I started to pay more attention to extractor's claw being clean too. It seems that the front portion of the factory mag spring gets weaker over 1-2K shot from the mag and front of the follower 'dives'. It binds it inside the mag body and causes FTF as bullet that is being stripped dives too. When extracted, since front of the next round in the mag is lower, it misallignes the angle at what empty case is pulled out and case binds on the extractor claw. Widening the gap a tiny bit and beveling extractor helps too. See similar for 1911s: http://www.m1911.org/technic2.htm
FTE may as well be associated with gummed up extractor claw. The gap is fairly tight and if gummed up from dirty powder, may cause rim to hang on the claw a bit longer and then slide catches the case.

It helps to polish the mag lips so that round gets stripped smoothly. Polishing may need to be done once in awhile as reloaded brass' rim may not be perfectly smooth and thus scratches the lips overtime.

+1 vote on checking/cleaning your extractor.

My Shadow shot flawlessly until about 7000 rounds then started having FTE's. I removed extractor by tapping out the pin (from top down) holding extractor and extractor spring in position and was amazed by the amount of crud/carbon hiding in the extractor tunnel or recess - chunks the size of rice grains. I was surprised by how much space there is underneath the extractor for crud to accumulate. It ran flawlessly after cleaning this out (for the next 3000-4000 rounds) - now an annual chore.
 
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