Magazine Spring Issue???

[Ontario Hunter]

I used a drill and rotary rasp. You could use a dremel and stone. You grind from the feed lip down below the contact area where the cartridge case touches the cartridge ( basically come down the radius of the cartridge.) Bit be aware this makes the cartridge move further left or right while feeding ie it may over shoot the chamber left or right. All changes need to be balanced- feed ramp vs magazine width vs feed lips adjustment.

I would advise a Dremel and purchase the optional carving flexible extension. It allows me to grind in tight spots. Remove the bottom metal and place the action upside down in gun cradle or Gun Butler. Easy to work on it that way. Here's images of my setup. Note that my carving extension is about worn out, hence the duct tape holding it together. I use this tool a LOT. And so does my daughter for taxidermy.

 

[Carsten]

Have you touched up the magazine follower as well to adapt it to the fatter 500 Jeffery cartridge? Kevin Weaver did that for me and it fixed the feeding problems on my CZ 550 in 500 Jeffery.

Yes I have.
That fixed my problem with the bolt sliding over the case rim as the right round will sit more to the left and therefore higher.

I fixed an extracting issue by fitting a new extractor.
I did a minor adjustment to the feeding ramp so my long loaded wide meplat solids do not jam between the feeding ramp and the magazine box.

My last issue is that the lower left round will sometimes jump out of the magazine when repeating fast and firmly.

I believe either a heavier magazine spring and/or more undercut under the left rail will fix that.

The heavier magazine spring is practically impossible to find, the undercut is an easy fix.
I think I have had most known issues with 500J feeding difficulties.

Last hurdle and I’m good to go.

@Ontario-Hunter, I have the Dremel extension.
Great for feeding ramps etc.

 

[cajunchefray]

That’s exactly the Dreme

I would advise a Dremel and purchase the optional carving flexible extension. It allows me to grind in tight spots. Remove the bottom metal and place the action upside down in gun cradle or Gun Butler. Easy to work on it that way. Here's images of my setup. Note that my carving extension is about worn out, hence the duct tape holding it together. I use this tool a LOT. And so does my daughter for taxidermy.
View attachment 564304View attachment 564305

I would advise a Dremel and purchase the optional carving flexible extension. It allows me to grind in tight spots. Remove the bottom metal and place the action upside down in gun cradle or Gun Butler. Easy to work on it that way. Here's images of my setup. Note that my carving extension is about worn out, hence the duct tape holding it together. I use this tool a LOT. And so does my daughter for taxidermy.
View attachment 564304View attachment 564305

That’s exactly the Dremel accessory I used to clean up the rails on a CZ 416 Rigby.
Well worth the money!

 

[Nhoro]

I found the deeper feed lips stop any rounds from popping out. You just need a fraction of an inch to make a fifference. But to complicate matters, the feed ramp height also impacts the round staying in the magazine. Higher ramp = earlier feed/ pop out. The ramp is also the recoil/ bolt bearing surface so be careful with that.

 

[Ontario Hunter]

Yes I have.
That fixed my problem with the bolt sliding over the case rim as the right round will sit more to the left and therefore higher.

I fixed an extracting issue by fitting a new extractor.
I did a minor adjustment to the feeding ramp so my long loaded wide meplat solids do not jam between the feeding ramp and the magazine box.

My last issue is that the lower left round will sometimes jump out of the magazine when repeating fast and firmly.

I believe either a heavier magazine spring and/or more undercut under the left rail will fix that.

The heavier magazine spring is practically impossible to find, the undercut is an easy fix.
I think I have had most known issues with 500J feeding difficulties.

Last hurdle and I’m good to go.

@Ontario-Hunter, I have the Dremel extension.
Great for feeding ramps etc.

Altering the follower may be necessary to correct problems with feeding the LAST round in the magazine. Always test the tuning of altered rails with AT LEAST two dummy rounds in the magazine. Three for tuning the right side rail and two in the magazine when tuning the left side rail. Once those stacked cartridges are feeding correctly, THEN go to work on the follower and feeding of the LAST cartridge in the magazine. It seems most mistakes are made tuning the left rail first with just one shell in the magazine. Then one can EASILY remove more metal from that rail than is needed. Removing too much metal from the follower in the final step (although unlikely) is not a big deal. Usually easy enough to replace it. Too much metal removed from the rail and that may be a fatal issue for the gun as a whole.

I'm not sure what advantage is gained by a beefier follower spring. I presume magnum action follower springs are longer? It's easy enough to increase the pressure of a standard spring by simply stretching it apart with two hands. I replaced the standard follower in my 404 build with a magnum one from New England Custom Gun. It filled the box nicely but I'm not sure it was even necessary. Many folks do these builds on standard Mausers and retain the original followers and springs. The NECG magnum follower was a bit wider and standard spring didn't fit tight in the retaining slot. Follower could jump off the spring when the floorplate was opened. I fixed this by slightly squeezing the follower in a vice at the point where retaining clips underneath are located. Presumably, magnum follower springs are slightly wider than standard ones?

I believe Hoosier Gun Works has magnum follower springs in stock. Or they did anyway.

 

[Ontario Hunter]

That’s exactly the Dreme


That’s exactly the Dremel accessory I used to clean up the rails on a CZ 416 Rigby.
Well worth the money!

I should add that my cheap ToolTown brand multitool is TEN TIMES better quality than actual Dremel brand multitool.

 

[Carsten]

I found the deeper feed lips stop any rounds from popping out. You just need a fraction of an inch to make a fifference. But to complicate matters, the feed ramp height also impacts the round staying in the magazine. Higher ramp = earlier feed/ pop out. The ramp is also the recoil/ bolt bearing surface so be careful with that.

In my rifle the lower round will jump out when the empty case is ejected but only if one is pulling the bolt back forcefully which is necessary to eject the case.
I am careful with the feeding ramp and only touched the lower edge, so strength is not affected.

Altering the follower may be necessary to correct problems with feeding the LAST round in the magazine. Always test the tuning of altered rails with AT LEAST two dummy rounds in the magazine. Three for tuning the right side rail and two in the magazine when tuning the left side rail. Once those stacked cartridges are feeding correctly, THEN go to work on the follower and feeding of the LAST cartridge in the magazine. It seems most mistakes are made tuning the left rail first with just one shell in the magazine. Then one can EASILY remove more metal from that rail than is needed. Removing too much metal from the follower in the final step (although unlikely) is not a big deal. Usually easy enough to replace it. Too much metal removed from the rail and that may be a fatal issue for the gun as a whole.

I'm not sure what advantage is gained by a beefier follower spring. I presume magnum action follower springs are longer? It's easy enough to increase the pressure of a standard spring by simply stretching it apart with two hands. I replaced the standard follower in my 404 build with a magnum one from New England Custom Gun. It filled the box nicely but I'm not sure it was even necessary. Many folks do these builds on standard Mausers and retain the original followers and springs. The NECG magnum follower was a bit wider and standard spring didn't fit tight in the retaining slot. Follower could jump off the spring when the floorplate was opened. I fixed this by slightly squeezing the follower in a vice at the point where retaining clips underneath are located. Presumably, magnum follower springs are slightly wider than standard ones?

I believe Hoosier Gun Works has magnum follower springs in stock. Or they did anyway.

I am with you a 100% about the tuning order.

My thought about the spring tension is that the harder the round is pushed in place under the feeding lips the less likely is it that it can move and jump out.
The follower will need to move just a little bit to let the round slip.

 

[Tokoloshe Safaris]

I will stick with my fordum tool best on the market

 

[Ontario Hunter]

In my rifle the lower round will jump out when the empty case is ejected but only if one is pulling the bolt back forcefully which is necessary to eject the case.
I am careful with the feeding ramp and only touched the lower edge, so strength is not affected.



I am with you a 100% about the tuning order.

My thought about the spring tension is that the harder the round is pushed in place under the feeding lips the less likely is it that it can move and jump out.
The follower will need to move just a little bit to let the round slip.

I suspect the exact opposite result: if the spring has too much tension, the rounds will jump the rails. Remember, cartridges are round (is that why they are called "rounds" ... hmm). The more energy applied to a round object, the more likely it will overcome friction and roll/move over an adjacent surface (e.g. the edge of the rail). As more pressure is applied by the follower, the width of the box/rails becomes more critical. The width of the box determines the angle of pressure on the round cartridges. According to Paul Mauser's cosine 30 degree formula my 416 Rem Mag box is too narrow for 404 Jeffery cartridges, especially at the shoulder area. But it works fine without any modification. Shells never jumped the rails from the get go. However, I am quite sure if I beefed up the follower spring I would have trouble. Right now the follower spring tension is rather weak (much softer than the spring in my Springfield 03A3) and the gun feeds flawlessly. Smooth as silk. I will say that tuning the extractor's spring tension had a much greater effect on smoothing out the feeding in my Mauser action. But that's another topic. Your problem is jumping the rails not smoother feeding.

 

[Ontario Hunter]

In my rifle the lower round will jump out when the empty case is ejected but only if one is pulling the bolt back forcefully which is necessary to eject the case.
I am careful with the feeding ramp and only touched the lower edge, so strength is not affected.



I am with you a 100% about the tuning order.

My thought about the spring tension is that the harder the round is pushed in place under the feeding lips the less likely is it that it can move and jump out.
The follower will need to move just a little bit to let the round slip.

Try reducing the follower spring tension rather than increasing it. Remove the spring and carefully bend downward (slightly) the top and/or bottom leafs. Reinstall and see if there's improvement. If so then your box below the rails is too narrow. Reducing spring tension might be a fix but probably not reliable without widening the box and adjacent receiver throat.

 

[Ontario Hunter]

When I say widen the box, I mean only the top where the round being loaded would rest against the sides. Below that width of box is essentially immaterial to feeding. The magazine box provides no structural strength to the action so don't worry about weakening it. For their early 404 rifles Jeffery cut away all sides but the back end of the action magazine box and used the stock cavity as a box. Those guns didn't blow up.

 

[Carsten]

Maybe I was not clear enough.
The last round is not a problem.
Only when there are more than one in the magazine.
When the top round is to the left the lower round will be to the right and vice versa.
Putting upwards pressure on the lower round will force the upper round to the opposite side and under the feeding lips.
When I apply pressure with my fingers under the follower with the floor plate open, I cannot provoke the round to jump out.
I will try with less pressure as well to test the other opinion.
However, when I have widened the action a bit under the rails I do not think it will be an issue at all.
When I get the time I will machine a new and wider magazine box as well.
I will let you know how it goes.

 

[Ontario Hunter]

Maybe I was not clear enough.
The last round is not a problem.
Only when there are more than one in the magazine.
When the top round is to the left the lower round will be to the right and vice versa.
Putting upwards pressure on the lower round will force the upper round to the opposite side and under the feeding lips.
When I apply pressure with my fingers under the follower with the floor plate open, I cannot provoke the round to jump out.
I will try with less pressure as well to test the other opinion.
However, when I have widened the action a bit under the rails I do not think it will be an issue at all.
When I get the time I will machine a new and wider magazine box as well.
I will let you know how it goes.

Ah! The last round is not a problem because it has the LEAST amount of spring pressure on it. So your follower is okay. It has no effect on the two rounds stacked above the round resting against it. The added spring pressure of more rounds stacked on top of the bottom round is at least partly causing the problem. That increases the spring tension. Obviously, increasing the follower spring tension even more is not going to improve things. It will almost certainly make the problem worse. If you can reshape the spring so there's less tension, the top two rounds may stay in place. But will the follower retain enough pressure to feed the third round? Again, reducing the spring tension may help but I suspect it would only be a band-aid solution. If you drop the butt on the ground with open chamber, rounds will probably still pop out of the magazine.

 

[Velo Dog]

Of the several CZ 550 rifles I had once owned during the years they were in production, all but my .500 Jeffery (from their so called “Custom Shop”), worked 100% perfectly, in the various calibers I had used.

The .500 however, would not feed any cartridge from it’s magazine, even though I had bought that rifle brand new, in the box.

Soft and solid alike would catch each bullet tip on the feed ramp, every time.

The best Gunsmith in Anchorage, Alaska ~ Andy Hawk of “Hawk’s Gunsmithing” fixed it quite simply by just slightly re-shaping the follower, on his milling machine and then hand filing the rails, again ever so slightly.

After that, it worked 100% reliably every time.

I read that a number of hunters did not like Model 550 CZ hunting rifles, apparently because they were not endowed with final shine & polish, resulting in a relatively small percentage of them not functioning correctly.

Indeed I was surprised and irritated, when after paying well over $3,000. USA dollars for their “Custom Shop” .500 Jeffery, it didn’t work.

In contrast, the other ones from their standard production line, purchased for less than 1/3 the price, all worked flawlessly for me (and all were split-hair accurate as well).

However, being a life long hunting rifle enthusiast, it is never insurmountable for me to have a rifle that shows real potential, tweaked on in order to make it then just perfect.

If I was a motor vehicle enthusiast, (and if a frog had wings) I would not sit down and cry if I saw a car I wanted but it had cheap tires on it or was painted poorly.
Instead, I would buy it and install new tires, have it properly painted, etc.

The large and robust CZ 550 Magnum action was a real peach and I lament it’s passing.

 

[colorado]

I agree Velo. The CZ 550 action is as solid as a bank vault (and almost as heavy lol). It's perfect for the 450 Rigby and 500 Jeffery.

 

[Carsten]

Ah! The last round is not a problem because it has the LEAST amount of spring pressure on it. So your follower is okay. It has no effect on the two rounds stacked above the round resting against it. The added spring pressure of more rounds stacked on top of the bottom round is at least partly causing the problem. That increases the spring tension. Obviously, increasing the follower spring tension even more is not going to improve things. It will almost certainly make the problem worse. If you can reshape the spring so there's less tension, the top two rounds may stay in place. But will the follower retain enough pressure to feed the third round? Again, reducing the spring tension may help but I suspect it would only be a band-aid solution. If you drop the butt on the ground with open chamber, rounds will probably still pop out of the magazine.

I understand why you came to that conclusion from my description, but it is a bit difficult for me to explain.

First of all my follower was not OK.

Here is a picture with the standard follower.
The bolt slips over the rim of the last round every time.

Next picture is where I milled 0,5mm of the follower moving the last round to the left end therefore also letting it sit higher.

I also tested the spring pressure issue.
I just opened the floor plate and put more and less pressure on the spring by hand and operated the bolt.

Less spring pressure makes the problem with the popping round worse.

A little more pressure and the round stays in place.

Second round perfectly aligned when the bolt is operated with additional spring pressure.

Here the round is starting to rotate and the butt is moved outwards, when there is less spring pressure.
The slightest touch and it jumps out.

Jerking the bolt just a little harder and the round pops.

When I add pressure to the follower spring the round stays aligned as the lower right round will force the upper to the left and under the rail.

Besides spring pressure, undercutting the left rail slightly will also help, hence my first question about how much.

A wider magazine well will probably do something as well and that will my next step.

 

[Ontario Hunter]

I understand why you came to that conclusion from my description, but it is a bit difficult for me to explain.

First of all my follower was not OK.

Here is a picture with the standard follower.
The bolt slips over the rim of the last round every time.

View attachment 565056

Next picture is where I milled 0,5mm of the follower moving the last round to the left end therefore also letting it sit higher.

View attachment 565057

I also tested the spring pressure issue.
I just opened the floor plate and put more and less pressure on the spring by hand and operated the bolt.

Less spring pressure makes the problem with the popping round worse.

A little more pressure and the round stays in place.

Second round perfectly aligned when the bolt is operated with additional spring pressure.

View attachment 565059


Here the round is starting to rotate and the butt is moved outwards, when there is less spring pressure.
The slightest touch and it jumps out.

View attachment 565058

Jerking the bolt just a little harder and the round pops.

When I add pressure to the follower spring the round stays aligned as the lower right round will force the upper to the left and under the rail.

Besides spring pressure, undercutting the left rail slightly will also help, hence my first question about how much.

A wider magazine well will probably do something as well and that will my next step.

Images were very helpful! I agree, it appears you need to remove metal from the bottom of the receiver where it meets the magazine. I would say probably a fair amount too. Will your bolt face then still be able to catch the rim of cartridges? If not you'll be looking at trimming the feeding rails at the back end ever so slightly. Be careful there! Those are fat cartridges. What caliber did your rifle begin life as? How do the magazine and receiver match up? If the receiver edge winds up a bit narrower than the magazine box, that shouldn't be a big deal if you can get the feeding corrected by working on receiver. The follower may hang up a bit during loading but cycling shouldn't be a problem.

I ordered a magnum follower from New England Custom Gun and that may have made life easier for my build project. It is wider and longer. And it's rail appears to be located further left. I still had to adjust it but my problem was the opposite of yours. The follower wasn't letting the round jump sideways and up into the bolt face/claw soon enough. Consequently, the bullet tip was pointed in the wrong direction. Note that the modifications are ahead of the back end at the place in cycling where the jump into bolt face must start so the bullet end is pointed into chamber. The trimming on follower rail tapers and ends at the point on the rail where the bullet should be well into chamber. Then the case rim can be fully pushed up into the bolt face by the follower. My follower ain't as pretty but what do I care? My rifle cycles flawlessly. When installed, one has to look carefully to tell the follower has been modified.