What am I looking for?

P

Potashminer

CGN Ultra frequent flyer
Uber Super GunNutz
Rating - 100%
586   0   0
Location
Western Manitoba
Today, I took delivery of a used CZ 527 carbine with 3 magazines included. I had made up some "dummy rounds" to verify feeding in another CZ 527 a few days ago - so I found those to try in this one - two magazines load up perfectly - the third one is a "problem child" - allows three rounds in, then as if the follower comes up against something hard - won't move. By messing with a tool, I can get that third round to move down, and then can load the next two rounds - but that third round initially feels to be solid - to be bottomed out. All three magazines feed about perfect - so the "issue" is just with one of the three - and is about loading, not feeding. I dismantled both the problem child and one that works fine - not seeing any obvious difference - so is likely something minor / something subtle - would be real PITA if that "problem child" was the only magazine on hand. Any suggestions how to go about finding what is causing this "issue"?
 
I just hate trying to figure out why a particular magazine fails...

My favorite way of fixing a problem detachable magazine was after an hour to use a large axe and my chopping block. One problem solved.

Maybe swap parts from the working magazines narrowing down what is failing...
 
Sounds like the follower is dragging on the sides when loading it, but when feeding is perhaps at a different angle and its getting through. Check if the walls or a wall is slightly compressed if you have a caliper. Got sat on by a big fella perhaps.
 
guntech said:
I just hate trying to figure out why a particular magazine fails...

My favorite way of fixing a problem detachable magazine was after an hour to use a large axe and my chopping block. One problem solved.

Maybe swap parts from the working magazines narrowing down what is failing...
Click to expand...

Yep, after thinking about it - is likely what I can do - dismantle a good one and the problem child - swap parts one at a time and see which one takes the issue along with it - if none do, then it can only be the box?? Or more than one part involved? Then have to figure out what it is about the "cause" part(s) that is (are) different from the part(s) that do work. As mentioned - is not readily obvious or apparent just now - would "really" suck to just have the one that does not work properly, but I do have two that do work - none are marked that I can find to show which was original to the rifle, and which were bought as "spares". I had been hoping this was not a totally weird issue, and perhaps someone had previously figured it out - but that axe and chopping block is completely understandable - from old days in underground maintenance at the mine, is NO LONGER REPAIRABLE - aka "BEYOND ECONOMICAL REPAIR" ("BER") - GET A NEW ONE!
 
Grain said:
Sounds like the follower is dragging on the sides when loading it, but when feeding is perhaps at a different angle and its getting through. Check if the walls or a wall is slightly compressed if you have a caliper. Got sat on by a big fella perhaps.
Click to expand...

A very reasonable guess - these do not have flat zig-zag springs - has coil spring under the follower - as if it can compress so far, then perhaps loop slides up beside the follower and jams it there - to be discovered - I simply can not see down in there to know what is happening - will be one of those 2 AM "eureka" discoveries to figure this one out!
 
Sorta "good news" and "bad news" - at least I know a few more things than I did earlier, but is not working yet.

I did as suggested above - coil spring installed bottom to top - nope, no change. Also tried coil spring front to back - still no change. Took all the guts from the "problem child" and installed in a "good" one - worked fine. Took the guts from a "good" one and into the "problem child" box - still have the "issue" - leads me to think problem is with the box, but so far I can not see or measure what is different between them. My good wife advises to keep fixing until I have "two" problem children, and neither works properly ... So, is set aside for now ...

It can not be complicated - four parts inside and a box - should be easy to figure out ... I am probably missing something simple and obvious ...

C64013B1-6472-4481-A04D-4D4BD64EED9D_1_201_a.jpg
 

Attachments

  • C64013B1-6472-4481-A04D-4D4BD64EED9D_1_201_a.jpg
    C64013B1-6472-4481-A04D-4D4BD64EED9D_1_201_a.jpg
    80.3 KB · Views: 294
Last edited:
Thanks, Darryl - I think I had noticed that - but totally confounds me that the follower, spring, cap and cover from the "problem child", all work fine in the "good" box - leads me to suspect something different between the boxes? I had discounted completely that there was anything lacking in the "guts" - but might be a "stacking" of teeny tiny errors??
 
That was my take as well, I would also say the springs are upside down, but that is just from working on other ones, not this model which I have not.
Have a bit of clear plastic? use it for the floor plate and a light and hold the plastic to bottom and load rounds and see if anything looks out of place
A bit of good tape may help, A paint stick cut to proper angle is good for pushing follower down to see if it hangs up.

Looking at picture, could be shadow, but bad one looks like it is dinted in on the mag side.
 
Is it just a trick of the light, or is that "Not" mag compressed a bit in the middle? About a quarter of the way own from the top and at the mid point, it looks to be a bit crinkled/bent inward - like it was squeezed and kinked a bit.
 
I see in the picture what you see - but not feeling or seeing that in hand, with exterior wiped off. With three rounds in mag - follower is at that "latching notch" on rear - so follower is already at or past that lower "kink" - then about 1/2 round lower stops solid - I tried with no rounds - just squared off wood piece - must not get follower just right - can not make it "catch" or hang-up with no rounds in there. 7.62x39 cases have taper from rim to shoulder - I can stack three without issue - I will try to cut a wood thing to replicate that angle of shoulder with three rounds on it - see if I can make that follower jam up at that point (or ANY point!!). Is confounding me that the "NOT" follower+spring+plate+cap installed into the "OK" box works fine, and the follower+spring+plate+cap of the "OK" mag shows the "issue" when installed in the "NOT" box. With calliper, I can not measure or see any difference at that point (or any point) on exterior of the boxes - frickin' voodoo or gremlins!!!
 
angle of the top of the spring looks different, not sitting flat and tweeked to the side, could be a problem

it's in the spring 80% sure
 
Potashminer said:
I see in the picture what you see - but not feeling or seeing that in hand, with exterior wiped off. With three rounds in mag - follower is at that "latching notch" on rear - so follower is already at or past that lower "kink" - then about 1/2 round lower stops solid - I tried with no rounds - just squared off wood piece - must not get follower just right - can not make it "catch" or hang-up with no rounds in there. 7.62x39 cases have taper from rim to shoulder - I can stack three without issue - I will try to cut a wood thing to replicate that angle of shoulder with three rounds on it - see if I can make that follower jam up at that point (or ANY point!!). Is confounding me that the "NOT" follower+spring+plate+cap installed into the "OK" box works fine, and the follower+spring+plate+cap of the "OK" mag shows the "issue" when installed in the "NOT" box. With calliper, I can not measure or see any difference at that point (or any point) on exterior of the boxes - frickin' voodoo or gremlins!!!
Click to expand...

It certainly sounds like the mag box is the issue given what you've tested. You've given the inside of the box a real good once-over to make sure there are no little burrs or anything that could be catching or snagging stuff?

It looks like there are little protrusions at the front and back of the mag body, could those be related to the problem? Looks like they're right about where the follower would be with 3 rounds loaded?
 
What's going on with the horizawntal window in the broblem child?
Looks darker on the left like an open vinder?
Like a tab pewshed in?

Yer brides theory stands pretty much correct.........:runaway:...........:cool:

Swap dem hookay'n nawt stickers around.
Kawnfewse dem stamped bawxizzs.
 
marshall said:
...

Have a bit of clear plastic? use it for the floor plate and a light and hold the plastic to bottom and load rounds and see if anything looks out of place
A bit of good tape may help, A paint stick cut to proper angle is good for pushing follower down to see if it hangs up.

...
Click to expand...

I am still looking for - and not finding - something "clear" that I can place on bottom, to be able to look inside to see what is making that "jam" - until I can see what is involved to do that, I do not have a clue what to "fix". Has got to the point that I will try to just replace that sub-plate that the bottom of the coil spring rests on - and see what is viewable through the little hole in bottom of that "cap" - when the "jam" occurs. Is sort of like trying to diagnose an "intermittent fault" in old days - can't fix something that is working properly when you test it, but is no doubt, at all, that it goes wonky at intermittent (unpredictable) times - is always a cause (used to be broken conductor in a wire that makes or or not depending on vibration or flex) - just have to find what that is / where is it - else, end up to "fix" away at stuff, that has nothing to do with the problem - becomes pretty much definition of "busy work" ...
 
If it actually binds, there 'should' be a rub mark on the inside of the bad mag, showing where it comes to a stop.

Long ago, in a previous life, I worked in a military small arms shop. For each magazine that we had in our system (five or six types, ranging from 30 round FN mags to Stirling SMG's, Lee Enfield rifles, and various Military Police issue handguns), we had a polished and hardened steel mandrel that we could stuff up in to the mag body, and proceed to wail on with a nylon faced hammer, so as to work out the myriad of dents and warps that came with being unloved, poorly cared for, and generally being handled like the stuff was "not mine".

Not to say you should run out and spend the money, but to say that it takes remarkably little in the way of warps and bends to hooper a mag body!

One thing I think I would try, is to cut some reasonably close fitting wood pieces, and use two of them to pinch the floorplate between them, and move the floorplate through it's travel through the body to see if you can find the bind point. If you can bind it, you should be able to peer in with a decent light, to see where (sides, ends) it is hung vs. where there is still a bit of clearance.

And, because I can be a bit of a blunt object at times, I would likely just see if I could spread the mag body sides a wee bit (say, a couple wooden door fitting wedges, and a filler block), on speculation that it may have been sat on or otherwise crushed 'just' enough. If you have a set of inside Calipers, you might be gentler, and set them for a light touch inside the mag body at the mouth, and follow the lines of the stamped details down, to feel if there are tighter spots.
 
You must log in or register to reply here.
Back
Top Bottom