Cz feeding problem

[Choupique]

Never saw this one before.

Last round is too far outboard and high.

 

[roklok]

Here is another pic of a shell that did pop out. You can see the extractor is not going to engage the rim. The is just a little bit to high and the extractor ends up pushing the case out with no control.

Thats what I figured was happening, the extractor was pushing the case out, not the bolt face. See post 24. So it could be a feedlip problem, follower problem, or extractor problem. How much of the extractor is engaging case head ? If the lower outboard corner of extractor was relieved this may solve the problem with no change to the engagement hook of extractor. A general rule is modify the cheapest part first. I would start with follower, then extractor. It wouldnt hurt to throw a new mag spring in, but I doubt that solves it.

 

[roklok]

The above case did pop out of the magazine. So I am thinking squeezing feed lips ever so slightly will fix it. What do you guys think.

I dont have a 550, but I thought the feed rails were part of the receiver, and therefore not able to be "squeezed". Are the feed lips part of the magazine box ?

 

[mitch4570]

It makes me nervous due to the fact parts for the CZ 550 are hard to come by. It always feeds the first four but I would really feel better if all cases feed corrrectly while hunting black death.

 

[mitch4570]

Thanks everyone for all the help.

 

[Ontario Hunter]

I also don't own a CZ but I did use my PH's 375 to shoot my first two buffalo. If his gun had cycled like yours, I would have left it in the truck and we would have hunted kudu instead! Did you not get a clue something was amiss when you almost had to hit it with a mall to get the bolt closed? There is a LOT wrong with the feeding besides the last round. Rough is an understatement. I suspect the feeding issues are due to multiple defects: extractor sprung too tight and/or wrong shape, follower the wrong shape (or it could be reshaped at base end to maybe work better), very rough machining of feeding rails (incredibly rough - closing the action sounded like a Punjabi 18 wheel tractor trailer running on rims!), and bolt face incorrectly machined (very likely). WAY to much force on bolt handle is needed to push the rim onto bolt face. I watched you beating on that bolt handle and my jaw hit the keyboard. I'm sure I could get that gun running slick but I'm pretty sure it's more than one issue. And I don't believe it's a weak follower spring. That would not be making this gun cycle so rough and sticky.

 

[Ontario Hunter]

It makes me nervous due to the fact parts for the CZ 550 are hard to come by. It always feeds the first four but I would really feel better if all cases feed corrrectly while hunting black death.

I would not want to have to cycle TWO rounds with that gun if hunting buffalo. You might sprain your wrist trying to reload it. Get it worked over before you go. You've got more to worry about than just the last round in the gun.

Over and over on this forum I read about guys who buy these CZ rifles and send them off to be fixed right out of the box. Apparently there is at least one gunsmith who's made quite a name for himself cleaning up CZ big bore rifles. They aren't ridiculously expensive rifles but still for their price the buyer should expect more, in my opinion anyway.

 

[EjectorSwipe]

How sure are you that this rifle has been work on by a gunsmith? That’s what mine fed like to start before a lot of work reshaping the feed rails and ramp. You shouldn’t have to put much force at all. I bet your brass is scratched and gouged by the feed rails, especially the belt.

 

[LimbNoMo]

In the video the rounds look beat from feeding multiple times. He has to put quite a bit of force to feed all the rounds.

If it really is a Matrix rifle, can’t emphasize enough that talking to them is where I’d start.

 

[Nhoro]

Fro mthe video, it looks like the round pops straight out, it is held by the feed lips. The fact that previous left side round fed ok suggest follower is at fault or possibly weak spring. I see you ordered a spring. The follower needs to exert a 60 deg pressure on the last round. If the pressure is too vertical, it pops out like in your video. I would suggest you try a little experiment. Get some cellophane and put some tape on the angled portion of the follower. You can also cut and layer tape to increase the angle and make it push more horizontally. I would try that, it is basically a free try that will show if the follower needs reshaping. Then a bit of polishing as per my thread that someone posted above and you will be good to go.

 

[mitch4570]

Thanks for everyones help. This rifle has both matrix upgrades. It looks rough but I am trying to cycle very slowly so you can view position of bolt and extractor. This rifle except for that last round cycles every bit as smoothly as the Tsavo I just purchased. I have shot about 100 rds through it and this is something that has just started happening. It's probably not going to Africa next year, that will be my 470 double and the Tsavo. So I have time to get it right.
Thanks again

 

[mitch4570]

How sure are you that this rifle has been work on by a gunsmith? That’s what mine fed like to start before a lot of work reshaping the feed rails and ramp. You shouldn’t have to put much force at all. I bet your brass is scratched and gouged by the feed rails, especially the belt.

Brass has been cycled many many times.

 

[mitch4570]

Fro mthe video, it looks like the round pops straight out, it is held by the feed lips. The fact that previous left side round fed ok suggest follower is at fault or possibly weak spring. I see you ordered a spring. The follower needs to exert a 60 deg pressure on the last round. If the pressure is too vertical, it pops out like in your video. I would suggest you try a little experiment. Get some cellophane and put some tape on the angled portion of the follower. You can also cut and layer tape to increase the angle and make it push more horizontally. I would try that, it is basically a free try that will show if the follower needs reshaping. Then a bit of polishing as per my thread that someone posted above and you will be good to go.

I will try this.

 

[mitch4570]

I will try again.

 

[CoElkHunter]

The above case did pop out of the magazine. So I am thinking squeezing feed lips ever so slightly will fix it. What do you guys think.

Could be, but I’d personally would have a gunsmith who knows what he’s doing check it out. On a side note, you need to put a little lubrication on the rails and bolt races. In the video, it looks to me the cycling of the bolt is pretty rough and should be much smoother. FYI.

 

[CoElkHunter]

Thats what I figured was happening, the extractor was pushing the case out, not the bolt face. See post 24. So it could be a feedlip problem, follower problem, or extractor problem. How much of the extractor is engaging case head ? If the lower outboard corner of extractor was relieved this may solve the problem with no change to the engagement hook of extractor. A general rule is modify the cheapest part first. I would start with follower, then extractor. It wouldnt hurt to throw a new mag spring in, but I doubt that solves it.

Yeah, it’s not the spring. My gunsmith Kevin Weaver carved out a “half moon” in the middle of the magazine follower which somehow fixed the problem of my third cartridge not cycling. I had never had a Mauser actioned rifle before my CZs. The geometry of the cartridges feeding from the magazine is great when it works but when there’s a flaw like mine had and the OP’s it sucks.

 

[Ontario Hunter]

Thanks for everyones help. This rifle has both matrix upgrades. It looks rough but I am trying to cycle very slowly so you can view position of bolt and extractor. This rifle except for that last round cycles every bit as smoothly as the Tsavo I just purchased. I have shot about 100 rds through it and this is something that has just started happening. It's probably not going to Africa next year, that will be my 470 double and the Tsavo. So I have time to get it right.
Thanks again

I have no clue how smoothly a Tsavo should cycle but that bolt is clearly hanging up EVERY time you cycle ANY of the rounds in the magazine. I just loaded up my 98 Mauser 404 and cycled it. The difference between cycling it empty or fully loaded is almost unnoticeable. Smoothe start to finish. No hang up. Your rifle is hanging up when the cartridges are FORCED onto the bolt face about half way to closing. A lot of force! The cartridges should move onto the bolt face much easier. Again, I'm quite sure the problem lays with the shape of bolt face, shape of extractor, claw, and/or extractor spring tension. Adding more follower spring tension will only increase the force loading the rim on the bolt face. In my opinion, that will just make it cycle more roughly.

According to Duane Wiebe the extractor should just barely hold a loaded cartridge when bolt is removed from the action.

Here's mine.

And here's my bolt face.

Another page from Wiebe's booklet re things to look for on bolt face that could be causing cartridge rims to hang up.

It is hard to believe a "specialist" gunsmith would send a reworked gun back to a client cycling cartridges like that.

Incidentally, his booklet shows how to convert standard action Mauser to 375 H&H.

 

[BlueFlyer]

It makes me nervous due to the fact parts for the CZ 550 are hard to come by.

Totally understand where you are coming from.
You say the action was previously optimised to improve the cartridge feed?
It appears that the tip of the extractor is contacting the rim and pushing the cartridge out of control feed. This may have been caused by the previous owner "tuning" of the cartridge feed! They may have taken too much material away - and you cannot easily put it back. This may be why the rifle was sold.
I definitely would not be squeezing the feed rails.
Try and buy a spare extractor so if the following mod fails you can go back to original.

With the combination of modding the feed rails and follower it now appears the extractor tip is contacting the rim on the last cartridge in the stack. Preventing the extractor from sliding past the cartridge rim, the rim bottoming out on the bold face and then sliding up under the extractor.
Please check that this is what is happening. as the video is too quick to study at this critical point. If the extractor tip is not touching the rim then I am completely wrong.
Do you know how to remove the extractor from the bolt?
If you do know how to remove the extractor, and you have confirmed that the extractor tip (highlighted in red) is contacting the cartridge rim, then I would use a diamond hone to just ease back the area highlighted in red, until the extractor tip at that point only just clears the rim.
Take it slow, polish a bit and reassemble and try, then repeat until the extractor tip is clear of the rim.
But make sure you have a spare extractor in case any changes affect the feed of the other cartridges.

 

[Choupique]

Should be easy for OP to identify if its the follower or extractor that is the primary issue. Compare the contact to a round that does feed from the starboard side correctly to the one that doesnt feed correctly. Since its just the last one, im inclined to say follower is the problem. That would be the best case. You can hack that all to hell and get another one relatively easily if that doesnt work.

 

[BlueFlyer]

Since its just the last one, im inclined to say follower is the problem.

Agree - depending on what mods have been done, it may not be as simple as putting in a new follower.
Worth trying though.