too much lead!

[chromecrow]

In my barrel that is. I have a 375win levergun that is the ultimate recycling firearm. I can shoot 10 boolits and when I clean it I get 1 back. I have slugged the bore. It measures .369 on the lands and 382 on the groove. I have shot boolits up to .384 still get leading. I can shoot my 255g Mountain Mold boolit over 7-7.5g of unique with only a speck or two of lead but if I crank it up to around 1200fps with any powder I get much lead. I am thinking about lapping the bore. Oh yeah I have only used plainbase boolits but I think I should be able to drive them at these modest velocities without the leading. What do you all think?

[David R]

I would shoot gas checks.

David

[StarMetal]

How new is the rifle? If new I think I'd shoot some jacketed out of it to smooth things up some. How's the transition from the throat to the rifling? Might also try a slower powder like a rifle powder, say 4198 for example. A dacron filler my help too.

Joe

[45 2.1]

Could you give us some more details, like boolit alloy, lube used, diameter sized, powder and charge used, etc.

[chromecrow]

I knew the gas check thing would come into play but I want to shoot PB. I have tried 4198 both H and IMR, 3031, RL7, 4227, AA1680, 2400, Unique, Bluedot and maybe a couple more. The boolit is straight WW but I have added some pure lead to one batch, I tried water dropping a few and that REALLY leaded up the bore. I thought that I might not be able to get it all out. I have used LBT blue and FWFL. The lead is heaviest in the first third or so of the barrel and I usually get the grey wash at the muzzle after only a few shots. Oh, the gun is a winchester Big bore that was used when I got it. I shot 20 rounds today starting with 10g Bluedot and worked up to 11.5 which clocked around 1250fps and got a pretty good wad of lead out on the first few patches. Accuracy was just over an inch at 50 yds even with the lead.

[StarMetal]

A dacron or kapok filler will take care of that grey wash, but not sure about the leading. Might try it and see. If it does and also cleans up some of the leading then I think you're dealing with a bullet base problem and gas cutting. I can't see how that's happening tho because you have shot a really fat bullet and still getting the leading. Hve you done a chamber cast to see how fat the throat is? Might be it's real fat and the gas is escaping past the bullet until the bullet seals off the bore, but by then the gas might have burned/blown the lube off the bullet and done gas cutting damage to it.

Joe

[chromecrow]

I have done a chamber cast and It does have a long fat chamber. I switched to 38-55 brass to attempt to solve this situation. The chamber seems to be a full size 38-55 and I had Mountain molds cut a mold to fill the throat and get out to the rifling. I am lost!

[Bass Ackward]

It measures .369 on the lands and 382 on the groove. I have shot boolits up to .384 still get leading. I can shoot my 255g Mountain Mold boolit over 7-7.5g of unique with only a speck or two of lead but if I crank it up to around 1200fps with any powder I get much lead.

I am thinking about lapping the bore.

Oh yeah I have only used plainbase boolits but I think I should be able to drive them at these modest velocities without the leading. What do you all think?


Chromecrow.

Your rifle has fairly generous proportions already. So I would not fire lap. Those .0065 tall lands will work one fine day. Just not this day.

With everything that you have tried, to include quality lubes, I can't possibly imagine a bore that rough that you couldn't feel it with a patch. And if it was that rough, you wouldn't be trying to shoot PB in it. And the fact that hard cast leads worse than soft when bullet diameter is not an issue. Plus the fact that you mention breech leading as to where it starts and after you lose seal you blow off your lube and get a grey wash out at the muzzle. To top it all off, you still get 1" groups!!!!!

Because of all these points, I have to ask, are you SURE you have all the copper out of that gun?

[Buckshot]

..................Your accuracy is very good regardless. The leading is an indication of a problem (duh!) which you know. I'm amazed that with the apparent amount of leading you're reporting, your accuracy was that good. I'm amazed.

Something, or a combination of somethings is at issue.

As a response to Starmetals question about a chamber cast and the throat, you replied: "I have done a chamber cast and It does have a long fat chamber."

Did you mean to say chamber? Or was that to mean chamber, throat and leade inclusive? What makes theorizing a problem difficult is the accuracy you're reporting. Usually leading in the beginning of the barrel points up to an undersized boolit, or no lube, or boolit damage, or an alloy unsuited to the charge.

Another thought is a constriction or reverse taper in the barrel, but that would also leade to leading further down, and then there is the accuracy you're getting.

.................Buckshot

[Lead pot]

If there is any copper in the bore you will be getting lead.
I am surprised that you get the accuracy and bullets not key holing with that much lead.
I shoot a .444 marlin with micro groove rifling and get just a small trace of flakes using 1/20 with DGL or my soy wax lube.

Kurt

[chromecrow]

The chamber measures 2.110 and is .405 at what would be the case mouth, then there is about .150 of throat that measures .384 then what seems to be a very smooth transition to the rifling. I have gotten good accuracy with several combinations but always with bad leading. I have probably fired 500 rounds through the gun and not even the first keyholed boolit. And there is lube all over the front of the chrony so it is riding all the way. The grey wash as i am calling it is when, from the muzzle, the entire bore appears grey. This grey is not the gross leading that appears in the other end but it is still lead, Right? In fact sometimes it is extremely difficult to push the first patch through because so much lead accumulates on it as it travels down the bore. Am I looking for too much? Maybe I should just sit down and be real still and when there is lead in the bore clean it and when theres not shoot it!

[David R]

You could mike a fired case inside the case mouth. This might help. My 222 was .231! For that rifle I shoot boolits that drop .228 and it shoots pretty good with no leading and reasonable accuracy.

You could also see in the special projects section about Outers foul out. Meybee it needs a good cleanin.

Gas checks.......

Good luck
David

[omgb]

You've got a tough one to be sure. Here's what I suggest. lets start by removing as many variables as possible.

1. Use a system like Foul Out to electolically remove any copper and or lead remaining in that bore. You can make your own or buy the system. Your choice but this is the only way without a whole lot of rubbing, that you can be sure that bore is clean.

2. After the electrolic cleaning, buff the bore with some JB Paste. A minimum of 100 in and out cycles should be used. You will have to change patches as they wear out and you will have to add paste. I would use an under-sized rod (as in those for 17 -22 cal) and a muzzle guard made of plastic or brass tubing so that nothing changes in the crown.

3. Cast up a bunch of bullets using WW but add about 5% tin. If your lead mix doesn't have enough tin, leading is going to happen. lead and Antimony do not really mix. The Antimony forms crystals around which the lead soldifies. Without tin, the lead is wiped onto the bullet as it fails to adhear to the Antimony.

4. Lube these bullets but don't size them. Run up a load with slow burning powder that should clock 1300 fps or so. Seat them out as far as they can go and still be chambered. This will all be single loading of course.

5. Give the bore a light lubing with Tetra grease.

6. Now fire ten or so rounds for accuracy. Check the bore. If the leading is gone or greatly diminished you're on your way. If not, clean it again as in step 1 and 2. Then, use LBT's firelapping kit as directed in the kit. That should fix the problem. Even constrictions in the bore will be ironed out as will roughness in the throat, on the cutting edge of the lands and deep in the grooves.

This isn't my theory, it's based on actual use. I went through H E double hocky sticks with a couple of guns until I adopted this system. I got it from Veral Smith over at LBT. When it comes to cast bullets and center fire smokeless he is "The Man" in my book.

R J Talley

[chromecrow]

4. Lube these bullets but don't size them. Run up a load with slow burning powder that should clock 1300 fps or so. Seat them out as far as they can go and still be chambered. This will all be single loading of course.


What do you consider a slow burning powder?

[rockrat]

Sounds like gas cutting to me, also. You might try a wad, kind of like one of the Walters wads they use for black powder shooting, on the base of the bullet and see if that stops the leading. Of course, after you make sure all the copper is out of the bore.

[StarMetal]

Chromecrow,

Don't lap the barrel. Don't use a wad...use a filler of kapok or dacron to fill the space between the powder and the bullet. Do not pack it in. A slow powder for a straight wall case are ones I believe you already used: 4198, 3031, etc.

I got grey wash in my Steyr M95 8x56R. Otherwise the load shot very well. I merely added a filler and the barrel shot clean. Try it.

Joe

[chromecrow]

I have considered using a filler and I already have some dacron. When using it do you take a tuft and loosely fill the space between the powder and boolit or should it go down on top of the powder or right under the boolit? So far this is the easiest thing to try.

[StarMetal]

Don't pack it or make a wad. You spread it out in the space between the powder and the bullet base.

Joe