CZ Barrel Leading

[onelight]

something has to have changed .
Why would a barrel and load that only occasionally gave light leading slowly begin to lead so badly? With no changes in load ,the way it is assembled , or the gun .
Is it possible that you were not getting the all the leading removed in in the past and it has gradually built up to the point it will lead quickly with any cast bullet ?

[Larry Gibson]

GITV

"Changed lead to new lead
Changed coating to different combination of coating "

Are you sure that is leading and not residue from the coating?

What is the composition of the alloy?

I ran and extensive test recently of 4 different PCings on the same 45 cal bullet. I loaded them in the 45 ACP and 45 Colt and tested in 8 different handguns and rifles. A couple of the coatings gave similar results as yours in some of the guns. I found it was the PC coating and not leading.

If you've a quantity of those bullets I suggest giving them a light coating of LLA (Lee liquid Alox) and let dry thoroughly before loading.

BTW; I've shot several thousand regular lubed cast bullets (96-3-3 alloy, sized .356 or .357, lubed with BAC) through my 9mm CZ 75 loaded over 4.0 gr BE w/o any leading. I've also shot a couple hundred PC'd bullets a member sent me. After 50 rounds the CZ barrel looked similar to yours but not as bad. It cleaned out easily with Hoppes #9 and a bronze brush with just a normal cleaning. I lightly coated the other 150 (cast of COWWs) 9mm bullets with LLA and shot them over the same load....no leading and no PC fouling. Give it a try if you can as your problem is the bullets, not the gun or the dies.

[JonB_in_Glencoe]

...SNIP

I have recently changed over from a stock 2 Tanfo to CZ shadow 2
The problem I have now it's the S2 barrel is leading up.

I might have forgot to mention.
We are using these CZs for a while now with the same load / heads. Same coating as well
Only recently the leading had become crazy. Previously once in a while you will find a little.

This is why I went to new lead coating and even commercially hitek made boolits

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I was under the impression from your first post that the S2 barrel had bad lead fouling from it's original change over, (from NEW, I assumed). If that isn't the case, I agree with Larry, that it's the coating, not the Gun/Load. BUT, I would have thought it would be easy to tell the difference between Lead fouling and PC fouling. When cleaning severe lead fouling, some of that should come out looking like shards of metal, whereas PC fouling would come out "NOT" looking like shards of metal.

[GTIV]

something has to have changed .
Why would a barrel and load that only occasionally gave light leading slowly begin to lead so badly? With no changes in load ,the way it is assembled , or the gun .
Is it possible that you were not getting the all the leading removed in in the past and it has gradually built up to the point it will lead quickly with any cast bullet ?

We cleaned the barrel properly every time.
Something has changed but I don't understand what. We will be doing more testing tomorrow

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[GTIV]

Maybe these pictures can give a better indication of whats going on.

I will try everything you guys suggest.
I have ordered a 0.358 sizing die and a new crimp die as well.

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[DougGuy]

Thanks for that information
What do you suggest?
Should try and do it and leave it alone?

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I would not attempt it without a dedicated tool post grinder with a 1/8" collet, and if the chamber didn't dial in perfectly on zero in the 3 jaw lathe chuck then I would have to go to a 4 jaw chuck, so right now that's about $1.000 worth of tooling and there is no way on planet earth to recoup the cost of tooling up just to do a case hardened barrel, I rarely have a call for a Shadow2 or a DW barrel for throating or forcing cone, and I have never been up against the wall in need of a 4 jaw chuck for my lathe. Yet.

I would not attempt to "Bubba" a throat into it with common abrasives and a split dowel or a dremel tool, although there are those among us who would and might get lucky and it works for them.

AND, if you DID happen to get lucky and throat it with a dremel tool, you are definitely going to break through the case hardening on the leade ins to the rifling, and now you have exposed soft steel which will erode rather quickly with full power loads. The same would happen if I did it with precision tooling, it would expose the soft metal underneath the case hardened layer and this would severely shorten the service life of the barrel.

Either you shoot it as is, and figure out the problems and solve them, or look to a different gun if no aftermarket barrels exist for it.

[GTIV]

I would not attempt it without a dedicated tool post grinder with a 1/8" collet, and if the chamber didn't dial in perfectly on zero in the 3 jaw lathe chuck then I would have to go to a 4 jaw chuck, so right now that's about $1.000 worth of tooling and there is no way on planet earth to recoup the cost of tooling up just to do a case hardened barrel, I rarely have a call for a Shadow2 or a DW barrel for throating or forcing cone, and I have never been up against the wall in need of a 4 jaw chuck for my lathe. Yet.

I would not attempt to "Bubba" a throat into it with common abrasives and a split dowel or a dremel tool, although there are those among us who would and might get lucky and it works for them.

AND, if you DID happen to get lucky and throat it with a dremel tool, you are definitely going to break through the case hardening on the leade ins to the rifling, and now you have exposed soft steel which will erode rather quickly with full power loads. The same would happen if I did it with precision tooling, it would expose the soft metal underneath the case hardened layer and this would severely shorten the service life of the barrel.

Either you shoot it as is, and figure out the problems and solve them, or look to a different gun if no aftermarket barrels exist for it.

This is what I needed to know
Thanks

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[FLINTNFIRE]

What coating do your bullets have ? though that surely looks like lead to me , curious to hear what works when you figure this out , I myself have had no powder coat fouling in my firearms , curious as to why the coated bullets from your experience and those of mr. gibson are leaving residue.

[Larry Gibson]

That definitely does look like leading at the muzzle in the last photos. As previously stated; the problem is the bullet, not the gun. I see no sense in trying to alter that gun to make that bullet work. Try TLing the bullets in LLA as also previously mentioned. If that doesn't cure the problem then I'd give up on those bullets and get others that don't foul/lead.

[GTIV]

Thanks will advise soon
Few more tests to do

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[trapper9260]

If you go with .358 boolits use the 38/357mag ex pander if you have one and then the seating die of the 38/357 ,I done that for one of my 9mm that takes that size boolit and no problems. it works for me.I also use the LFD of the 38/357 on the 9mm case. Also I go with Larry for what said.

[Dusty Bannister]

GTIV
I have gone back through this thread trying to see where the problem might have started. You are loading a cast bullet of about 126 grains in 9MM S&B cases with 4.3 grains of S 121 powder. These cast bullets are seated to 28MM and you can turn the cartridge in the barrel when so seated. Your alloy might be 14-15 BHN. You are powder coating, I think, but am not sure what source or baking procedure. You have found significant leading the length of the bore after 50 rounds. The barrel is completely cleaned of residue before another shooting session.

So, Somchem Data says for a 126 cast lead bullet you have a suggested starting load of 3.8 grains and a max load of 4.2 grains. You are over max! The 28 MM is for the Eagle cast 126 grain bullet and you may be using something different, and therefore the cartridge AOL per your comment might be a bit short of the lands. Can you seat the bullet out a bit further and still feed from the magazine? Go back to the starting load and work up the load again. You need to CHECK frequently to determine if the leading is starting at the chamber end, and building up to include the muzzle end. That will suggest a bullet diameter issue. It also might suggest that the hot gas is gas cutting the coating off the side of the projectile before it seals the bore after engaging the lands.

When you change one thing, you should work up the load again checking for pressure or other issues. I think you failed to do that and stepped over the line and now are having to clean leading from the barrel. It is also a good idea to condition the bore after cleaning with a gun oil or a soft wax bullet lube. You may be trying to shoot a powder coated bullet down a bone dry bore that might now have small scratches from aggressive cleaning and that needs to be corrected. Maybe if you start at the beginning, you will find your way forward a bit easier? Dusty

[swheeler]

Dusty Bannister gives some good advice, especially backing off the powder charge to see if that stops it, that would be my first move/test. I did the HiTeck coating thing before PC and had a couple barrels that came out looking similar, not quite that bad, to yours in rifles with plain based bullets. I've had much better luck with powder coat bullets, but it's not a cure all, alloy still has to be up to task and fit of bullet still has to be right. For leading that bad a stainless steel tornado brush will help clean it up quickly, I like to run it from chamber to muzzle with a clean sheet of paper under the muzzle, you'll know if it is lead or not, just a few strokes before your regular cleaning regiment does wonders. I would think just 10 rounds then check the barrel for build up and where. Good luck

[Papercidal]

I went through the same issue a while afterI switched from Glock to a shadow 2 for uspsa (the Glock polygonal barrel much like your tanfo is very forgiving of lead bullets) I had quite a stock of cast coated bullets when I switched to the cz and they worked perfectly with no leading but my next batch of bullets leaded terribly.

I had made several changes at that time any of which could have been the culprit I had.

1) switched from a 155grain bullet to a 140 which requires a bit more velocity to make power factor.

2) I had ran out of my 4:1 blend of pure lead:foundry type which was basically hardball alloy and switched to range scrap mixed with Lino.

I took a while to get to a point where I was getting satisfactory results again I went through the following process.

1) I sized the 140gr bullet to .358tgr this reduced leading quite a bit but did not eliminate it totally.

2) I cast up a batch of the 155gr bullet sized @ .358 and had almost no leading but I wanted to use the 140gr

3) I tried water quenching the 140 after the final coat of hi tech and this reduced the leading still more but would still get tumbling bullets after about 500rounds due o leading.

4) I won a gift certificate for some commercial bullets at a match and even though they where sized at .355 I got no leading at all.

5) I ordered some hardball alloy from Missouri Bullets (under 2.50 a pound) and cast up a batch of the 140gr bullet sized to.358 and coated with hi tech without water quenching and I have not cleaned my pistol for around 2500 rounds and still have no leading.

In conclusion I believe the cz needs a relatively hard bullet sized on the large side.
My first step in troubleshooting this would be to get some known hardball alloy and size to .358.

[onelight]

I went through the same issue a while afterI switched from Glock to a shadow 2 for uspsa (the Glock polygonal barrel much like your tanfo is very forgiving of lead bullets) I had quite a stock of cast coated bullets when I switched to the cz and they worked perfectly with no leading but my next batch of bullets leaded terribly.

I had made several changes at that time any of which could have been the culprit I had.

1) switched from a 155grain bullet to a 140 which requires a bit more velocity to make power factor.

2) I had ran out of my 4:1 blend of pure lead:foundry type which was basically hardball alloy and switched to range scrap mixed with Lino.

I took a while to get to a point where I was getting satisfactory results again I went through the following process.

1) I sized the 140gr bullet to .358tgr this reduced leading quite a bit but did not eliminate it totally.

2) I cast up a batch of the 155gr bullet sized @ .358 and had almost no leading but I wanted to use the 140gr

3) I tried water quenching the 140 after the final coat of hi tech and this reduced the leading still more but would still get tumbling bullets after about 500rounds due o leading.

4) I won a gift certificate for some commercial bullets at a match and even though they where sized at .355 I got no leading at all.

5) I ordered some hardball alloy from Missouri Bullets (under 2.50 a pound) and cast up a batch of the 140gr bullet sized to.358 and coated with hi tech without water quenching and I have not cleaned my pistol for around 2500 rounds and still have no leading.

In conclusion I believe the cz needs a relatively hard bullet sized on the large side.
My first step in troubleshooting this would be to get some known hardball alloy and size to .358.

I gotta ask if line 4 .355 had no leading why do you want .358 ? Are .355 not accurate in you gun ?
Just curious .

[Papercidal]

I gotta ask if line 4 .355 had no leading why do you want .358 ? Are .355 not accurate in you gun ?
Just curious .

I’ve never been able to get my own Bullets sized anything below .357 to not lead I suppose I could try sizing them smaller but it’s less effort to size from .359 to .358 than to go smaller and they case gauge, chamber, are accurate and don’t lead so why work my arm any more than needed that and I don’t have a sizing die that small.

[onelight]

I’ve never been able to get my own Bullets sized anything below .357 to not lead I suppose I could try sizing them smaller but it’s less effort to size from .359 to .358 than to go smaller and they case gauge, chamber, are accurate and don’t lead so why work my arm any more than needed that and I don’t have a sizing die that small.

That makes sense.

[GTIV]

Thanks to MZ
We changed the powder to S221 and it seems the leading has disappeared compared to what we had. The PF was low though as it's a new load but there is light at the end of the tunnel

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[mozee]

Awesome news. Glad it’s sorted. How many rounds did you push through?


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[GTIV]

Louis shot about 50 rounds and it was much cleaner.
He needs to get the load right and we will test further tomorrow

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