Why am i getting leading?

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Death from Afar

New member
Team, i have been running what i think i are "middle of the road" loads through my Mod 29- literally half way in the manual. WIth cast bullets, there is still some leading going on, which requires a decent scrub about every 200 rds. Can I always expect leading with a cast bullet, or should I ease back a bit more? Thoughts?
 
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aarondhgraham

New member
Soft lead maybe?

I bought some bullets from a local caster and had the same problem,,,
It turns out he was using very soft lead in his pot,,,
That meant that even with a light target load,,,
It was enough to vaporize the bullet base.

Just a thought,,,

Aarond
 
D

drail

Moderator
Bullets may be undersized for the bore dia. or the cylinder throats may be undersized (relative to the bore) and are swaging the bullets down so that they exit the cylinder undersized for the barrel (cylinder throats can be reamed) or the bullets are too hard and they're not obturating (swelling at the base) when the pressure spike hits them. If the bullet does not obturate and swell to seal the bore gases will get around the bullet and it will lead the bore. A "soft" bullet will generally obturate and seal off the bore unless you're trying to drive it at very high velocities. You can "slug your barrel (drive a soft lead bullet through it with a brass rod and a mallet) and measure the land and groove diameters engraved on the bullet. Then measure your unfired bullet and see if it is under or over the groove dia. of the barrel. If the bullet is not at least one thous. larger than the bore's groove dia. you'll get leading at almost any velocity. Even if everything is perfect you can expect to get a little bit of lead residue, usually in the cyl. throats and in the forcing cone area and the first inch of bore. But this should clean up pretty easily with a brush or a Lewis Lead Remover.
 
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carguychris

New member
What kind of powder are you using? Try a non magnum powder like Herco or W231.
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+1, and I also suggest Trail Boss.

FWIW some faster powders burn unusually hot and are known to cause more leading than you'd think they would; Titegroup is known to do this, but it's still my favorite .38Spl powder because of how well it shoots. :)
 
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jhenry

New member
Death, tell us the exact load, powder, primer and bullet to include diameter and weight please. That will be a good start. I have an opinion now, but I would like to see the data first.
 
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GeauxTide

New member
DFA, 10gr of Uniques should bring 1000-1050 with 240s. I suspect, as others have already posted, the bullets are too soft. Cast bullets and Unique are pretty dirty, but the accuracy is worth it, IMHO. 200 rounds doesn't sound too bad, unless your accuracy tails off. One other suggestion, try 8 and 9 grains and see if there is any difference.
 
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Hal

New member
jHenry, its ten grains of unique on a 240 grain cast bullet...thanks!
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I had a similar experience using ~ 9 grains of Unique under a 240 gr swaged lead bullet. The 240 grain Hornady lead hollow point. Much softer than the cast bullets you're using.

I wanted a "hot special"/ "low magnum" every day plinking load @ about 1100 fps.

I solved the leading by switching over to 17.5 grains of Alliant 2400.

A bonus here too is the 2400 load burns cleaner than the Unique.

It shot very well out of my Model 29 4" barrel and also my Winchester Trapper.

One Question- will you always get some leading, is it just a question of degree? Thanks!
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Yes/no/maybe....
I strongly suggest going back and reading and digesting the links rclark posted.
That info (IMNSHO) is spot on.

Also - two steps which are necessary to the successful use of lead bullets.

1.) Slug the chambers/bore - then size your bullets accordingly. S&W used to be very good about keeping to .429" on the Model 29. It still doesn't hurt to verify it though.

2.) Lube. Those grooves between the driving bands are there for a purpose. They should be filled with lube. If the lube has fallen out - which is very common, switch to a different brand/supplier.
I mentioned the Hornady 240 gr swaged lead bullet above. Hornady uses a dry lube which I have yet to see come off the bullets.
 
T

tulsamal

New member
I agree that the bullet hardness is the #1 factor. Properly hard cast bullets can be driven quite fast without leading. As long as #2 is attended to: proper bullet diameter for YOUR barrel.

Even with proper bullets of the proper diameter, you do run into "problem guns." Then you read this recent article and follow his steps!

http://www.gunblast.com/FerminGarza-Firelapping.htm

Gregg
 
D

dahermit

New member
Can I always expect leading with a cast bullet,
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No. Those of us who have been casting since the sixties know that, "correct loads do not lead." You may have to experiment with different things, but that is a true statement.
 
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jhenry

New member
Afar, that charge of Unique would certainly obdurate the bullet to such an extent that all other things being right, you should have very minimal leading. I suggest slugging the chamber mouths and barrel, and checking the throat. Also when checking the barrel feel for a slight constriction at the juncture of the barrel and frame. That is more of a potential Ruger problem but it pays to be careful. It is easy to have throats enlarged, not so much making them smaller. I also suspect you may be running out of lube, or have an inadequate lube to begin with. Maybe both. The Keith design has a single very deep lube groove for this reason. Many commercial cast bullets have a much shallower grove with rounded edges for ease of manufacture. In a perfect scenario you would find some lube in a star pattern at the muzzle. This indicates you have good lube all the way past the muzzle. After slugging, and assuming all is well, I would try 2400 to achieve the desired velocity and check for leading. You may have the solution right there with no more travail.
 
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