Checkmate Mag Nose dive

[Sfisch0311]

So I am having an issue with my mags nose diving and in turn causing feeding issues. I'm loading to 1.160 OAL. 2 of my 170s I only feel comfortable loading up to 20 rounds and the other just 25. I should be at 29 rounds. Any tips or ideas would be appreciated, thanks!

[arkadi]

Quoting Beven Grams:

 

Quote

The “nose dive” feeding issue you are describing is common with both the short and long mags made by CZ, at a rate of at least 50%. At any point in the round count that the mag holds, the top round must be supported by the round underneath it, in a “nose up” position, to the angle of the feed lips. You can check this condition by loading the mag, and checking to see if there is a gap between the top round and the round underneath it. You should be able to push the nose of the top round down, release it and have that bullet, and the one under it, pop back nose up, with no gap.
 
This nose diving problem is caused by an incorrectly shaped tube, in the tapered part of the tube, not in the feed lip dimensions. Yes, the feed lips need to be a certain width, but also parallel with each other, not wider at the front, allowing for more nose up position. If there is no nose up pressure to begin with, it will just push down when the slide try’s to push it forward, into a nose dive to the bottom of the feed ramp.
 
To fix this problem, the tube needs to reshaped with special tooling, in the tapered part of the tube. I do offer this service for $20.00 plus return shipping. My follower kit is a must to finish creating a reliable package at this point, which you have already purchased.
 
If you have any other questions, give me a call and I will be happy to discuss.

 

Use 2011 mag for a reference of proper double to single stack transition. It is advisable to have chain pliers to help restore proper feed lips dimensions. Feed lips front will expand during reshape, but if you overdo hammering them back to spec the pliers become very handy.

 

 

 

Also, 

 

Edited August 3, 2018 by arkadi

[Lastcat]

[mro111lland]

Before you go all Frankenstein on your 120$ mags try new springs. Are they dirty take them apart throw them in your tumbler with some car was in it for an hour or so. Nose dives ( in my experience) are generally caused by week springs or the follower hanging up on the inside of the tube

[Lastcat]

1 hour ago, mro111lland said:

Before you go all Frankenstein on your 120$ mags try new springs. Are they dirty take them apart throw them in your tumbler with some car was in it for an hour or so. Nose dives ( in my experience) are generally caused by week springs or the follower hanging up on the inside of the tube

 

Have you tried the 2 examples above? Then you really don't know what you're talking about. I'm not tumbling my CZ mags with "car wash"? No thanks.

[Matt1]

I believe he meant car polish.

I used to use polish in the outside of my TS mags to keep the rust at bay.




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[mro111lland]

Stupid autocorrect I meant car Wax. Any yes I've tried the examples I'm just saying try the simple things first 

Edited August 4, 2018 by mro111lland

[11287]

I just sent my Czechmate 170mm mags to Bevin.  I got back three mags that with reliably hold and feed 29 rounds.  Bevin called me before sending them back.   He told me if I tried real hard, I could probably get 30 rounds in the mag.  He also told me to never attempt that.  The mags run perfect now and have so for a couple years.

[pskys2]

Never had much trouble with my 140's, but like the idea of polishing them.

Don't have car wax, but may try it with brasso.

As in schmoozing, slick is better...

Edited August 6, 2018 by pskys2

[kneelingatlas]

On 8/3/2018 at 12:09 PM, Sfisch0311 said:

So I am having an issue with my mags nose diving and in turn causing feeding issues. I'm loading to 1.160 OAL. 2 of my 170s I only feel comfortable loading up to 20 rounds and the other just 25. I should be at 29 rounds. Any tips or ideas would be appreciated, thanks!

 

Are you loading JHP?

[Sfisch0311]

1 minute ago, kneelingatlas said:

 

Are you loading JHP?

No, just RN 124s

[Sfisch0311]

I'll see if I can get them tuned myself. If not I'll just send them to Grams lol.

[arkadi]

For your reference, almost single stack on top - then the mag works and there is no gap.

 

Edited August 7, 2018 by arkadi

[blindmarksman]

On 8/3/2018 at 4:27 PM, Lastcat said:

Very cool