Please explain "Leading"


PDA






juk
May 27, 2010, 09:30 PM
Ok, I am fairly new to reloading, but have been shooting 45 and 308 reloads with great success. Recently, I've been on a kick about getting my 45ACP loads just right instead of just going for a load in the middle of the pack. I have been loading Missouri's 200 grain "XD" bullet over 4.0 grains of clays. It is more accurate than factory blazer in my gun ( CZ 97), but is a tad smokey, It does have leading in about the first 1-2" of barrel. Loads have a medium crimp with Lee FCD.

So, I guess my question is: What causes leading? I know that leading in different locations in the barrel mean different things. What causes that? And, how would I go about reducing the leading in my barrel? I do have a pound of "Bullseye" but will have to wait a while until I order more bullets. Thanks for all of the help.

If you enjoyed reading about "Please explain "Leading"" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Robert101
May 27, 2010, 09:36 PM
Well, I'm not a chemist but lead has varying degrees of softness/hardness depending on the antimony present. A harder lead bullet is likely to have a higher melting point. The hot gases from the combustion of the powder cause primarily the base of the lead bullet to melt and deposit streaks into the barrel. A copper gas check is used to push lead bullets to a higher speed by lessing the amount of lead deposits. Some leading is not a bad thing. Just remove the lead after shooting and all is good.

243winxb
May 27, 2010, 09:53 PM
Leading by our definition is shearing. http://castboolits.gunloads.com/showpost.php?p=700845&postcount=18 My definition is when there is a loss of accuracy. Here is what Lee has to say about leading. Cast bullet leading

A clue to what is causing the leading is where the leading first begins to appear. If it appears near the chamber, chances are that bullet diameter or hardness are the cause.

A diameter too small and/or too hard an alloy will allow high pressure gas to leak past the bullet, which erodes the bullet and leaves leading near the chamber.

If the leading first appears on the leading edge of the rifling (if you imagine the bullet being pushed through the barrel, you will note that one edge of the rifling does most of the work of imparting a spin to the bullet. This is the edge you see when you look through the barrel from the breech end) the bullet might be too soft, and/or the velocity too high.

If the leading appears in the second half of the barrel, the bullet is running out of lube. You should see a star shaped pattern of lube accumulate on the muzzle. This is an indication that there is a little excess lube. http://www.leeprecision.com/cgi/faq/index.cgi Some say the Lee factory crimp die can size the loaded bullet smaller in diameter with its use. :uhoh: :D To get leading out, i still use the plain Hoppes #9. Wet bore, let it soak a day or two, brush, repeat as needed. Old slow method.

juk
May 27, 2010, 09:55 PM
Another question I meant to ask was: What is the best way to remove leading? I use Hoppes #9 Benchrest. It gets a good part of it out, but there is still some left in there.

Thanks for the links 243. Mine starts at the rifling.

Randy1911
May 27, 2010, 10:09 PM
The best way I have foujd to remove barrel leading it to wrap a small piece of Chore-Boy copper pot scruber around the bore brush. It will make the proce go much faster and do a better job.

Steve C
May 27, 2010, 10:29 PM
It does have leading in about the first 1-2" of barrel.

The short answer is: The bullet you choose is too hard for the pressure you are able to load at using the .45 ACP and Clays. Leading at the chamber end of the barrel shows a bullet that's not bumping up and sealing the bore which allows hot gasses to bypass the base and melt lead from the side of the bullet into the bore.

The 200 gr XD bullet is an 18 BNH hardness bullet for action targets. The "optimum" pressure for 18 BNH using the formula in the Missouri technical data of Optimum BHN = CUP / (1422 x .90) would be found by BNH x (1422 x .90) = CUP which calculates out to 23,036 CUP (the old pressure measurement). A maximum load from the Hodgdon website of Clays is 4.3 grs and produces 17,000 CUP. The old SAAMI standard for the .45 ACP was 19,900 CUP before the change to using PSI where the equivalent is 21,000 PSI.

For the standard velocity and target level loads and the one you currently use it would be better to use the 12 BNH bullets.

You can try to change powder and push pressures up and it may stop the leading or simply shoot this load, clean the lead up, and next time order the softer bullet.

sharptailhunter
May 27, 2010, 11:15 PM
Like Randy said, use a piece of Chore Boy brand pot scrubber wrapped around an old bore brush. It's an all copper scrubbing pad so it won't hurt your barrel. I use a 30 cal brush for my .40 barrel. It scrubs out the lead slickety slick. I then follow up with some Hoppes #9 and she's like new. Takes about 49 seconds to do it right.

GP100man
May 27, 2010, 11:24 PM
Wet with ya favorite solvent & a few passes later DONE !!

http://i746.photobucket.com/albums/xx110/GP100man/choreboyscrubber.jpg

juk
May 27, 2010, 11:27 PM
Thanks for the info everyone. Steve, that was a very informative post, and makes sense. When I chose the bullet, I went off of Missouri's reputation and what looked good. I now know there is more to consider than looks. I still have a few hundred loaded rounds, so I will just chore-boy the barrel until these are up, then look for a softer bullet and try those.

Steve, I think that you would be a good candidate to start a "sticky" about leading, leading issues, and Brinell harness/cartridge issues. LOL Thanks, again.

sharptailhunter
May 27, 2010, 11:37 PM
I think the world of Missouri Bullets. Is the leading so great that it is affecting your accuracy or causing signs of elevated pressure? I get some leading with my MBCs but it doesn't affect my accuracy at all and the amount of leading is minimal. I certainly think it's ok to try different brands of lead bullets but I have a hard time thinking that the leading is so bad that you should discredit MBC so readily. From my personal experience, I switched brands of powder (went from Titegroup to AA#7) and got much better accuracy, a lot less smoke and less leading. So, I'm just saying there are A LOT of other viarables than just the brand of bullet.

Walkalong
May 27, 2010, 11:55 PM
The short answer is: The bullet you choose is too hard for the pressure you are able to load at using the .45 ACP and Clays. Leading at the chamber end of the barrel shows a bullet that's not bumping up and sealing the bore which allows hot gasses to bypass the base and melt lead from the side of the bullet into the bore.
Yep. Try the 12 BHN bullets from Missouri Bullets

Yep, lots of variables. It is not the "brand" of bullet, it's the hardness to pressure ratio.

Yes, some powders do better with lead than others. W-231 is a very good one with lead.(But so are others) 1000's of lead bullets with W-231 and never ANY leading in my .45 barrels, and I do mean never. I have never had to clean any lead out of a .45 barrel. I can't say that for other calibers. I have had to tweak loads in other calibers to get them lead free.

HOWARD J
May 27, 2010, 11:58 PM
When I was shooting lead bullets--I used a LEWIS LEAD CLEANER for handguns.
It pulls a copper or brass screen down the barrel--couple passes & the lead is gone.
I don't use it anymore as I only use Jacketed or plated bullets.

juk
May 28, 2010, 12:40 AM
Honestly, I don't think I could say a negative thing about MBC. I wasn't implying that the bullets were to blame for anything, only my lack of knowledge of selecting lead bullets. In fact, I was planning on getting a different bullet from MBC. I was simply saying that now I know something about lead bullets.

On a side note, I am a self-taught reloader. I do alot of reading on forums, books, etc. I am very cautious in my reloading, often double and even triple checking my progress. I don't have a shooting "mentor" to learn from or anyone to sit me down and say "this is how you do it". With that said, my leading may not be bad at all; it may just be minor. I don't have the experience under my belt to say whether or not it is bad. I just know it is there and that it can be prevented. I do appreciate the advice and knowledge.

Lee Roder
May 28, 2010, 02:02 AM
Yep, lots of variables. It is not the "brand" of bullet, it's the hardness to pressure ratio.

Yep, and degree of leading also depends upon the bullets diameter relative to your "bore". If your bullet is too skinny, they skid and don't obturate as they travel down the bore. I know shooting .356" bullets (measued from pulled privi partisen) out of a 38 special with 0.359" throats leads like crazy!

the chore boy copper pads work as well as the llewis lead remover

Tim the student
May 28, 2010, 02:27 AM
Is Chore Boy a regional thing? I don't recall ever seeing it, but I haven't been looking very hard either. I'll need to keep my eyes open I guess.

Steve C
May 28, 2010, 03:54 AM
No use to give up on Missouri, they sell a 12 BNH 200 grain just for target loads.

All I posted was information that one can find in the Technical tab on Missouri's website.

The trick is to pick the right hardness for what you want to load. I buy softer lead bullets for the .38 spl and the .45 acp as they're relatively low pressure cartridges. I buy the harder lead bullet for the 9mm, .357 mag and .41 magnum with their higher pressures.

I went though a lot of frustration with lead bullets before the internet. With the free exchange in information on the internet I think I have it somewhat figured out with the help of other lead bullet users and casters.

Steve C
May 28, 2010, 04:21 AM
delete

Walkalong
May 28, 2010, 07:57 AM
before the internet.we had books (http://www.thehighroad.org/attachment.php?attachmentid=120451&d=1272669229) and gun mags etc.

Here is a good thread on lead (http://www.thehighroad.org/showthread.php?t=520330).

243winxb
May 28, 2010, 08:51 AM
When casting your own bullets >You can get hardness with lead & antimony. If you lack tin, you get leading. If the alloy is not fluxed when casting, the tin just floats on the top. Bullets cast this way will lead. See photos of leading here. http://www.photobucket.com/joe1944usa Oven heat treating bullets to harden them, seems to be another easy way to lead a bore. I will keep air cooling, and use NRA type lube, 50/50 bees wax/ Alox.

Gadzooks Mike
May 28, 2010, 10:03 AM
Not CUP.

CUP =/= PSI It's like substituting kilometers for miles. You can do it all day long, but it doesn't make it correct.

The 1422 is used to convert BHN (which is measured in Kg/mm^2) to PSI. It doesn't convert anything to CUP.

Funny thing is, I've discussed this with Brad in some emails, and he said he got the formula from here: http://www.lasc.us/Brennan_3-3_CastBulletHardnessRequirements.htm but that's in PSI, too. It's also shown in PSI in Lee's book.

Goodness, just about everyone in this forum measures things to a tenth of a grain or less, you'd think we could get something like this a bit closer to accurate.

RandyP
May 28, 2010, 12:03 PM
Chore Boy is available at most all big name grocery, hardware and big box stores. here is what the packaging looks like:

http://www.choreboyscrubbers.com/products.htm

Tim the student
May 28, 2010, 12:07 PM
Thanks RandyP. I'm pretty sure my grocery store doesn't carry it, but I'll look in the places you mentioned.

Jeff H
May 28, 2010, 01:14 PM
Choreboy isn't the only brand you can use. Any brand that is pure copper will do the trick. Just take a small magnet to the store and make sure whatever you buy isn't copper plated steel.

fourdollarbill
May 29, 2010, 07:10 AM
Is Chore Boy a regional thing? I don't recall ever seeing it, but I haven't been looking very hard either. I'll need to keep my eyes open I guess.
I buy the "Oh Cedar" brand and it is pure copper.

OR*** I just shoot a few gas checked bullets at the end of the day and any leading gets scraped out - clean as a whistle.

If you enjoyed reading about "Please explain "Leading"" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!