Causes for barrel leading

[MLR]

I keep seeing articles where when the subject of barrel leading is brought up the blame instantly is blamed on to soft an alloy. If not that then a rough bore. Am I the only one who cringes every time someone says that?
In my experience most leading that I have encountered has been caused by undersized bullets more than anything else. With undersized bullets I have experienced more leading with a hard alloy than I have with a soft one. The soft one will to bump up to bore size upon firing whereas the hard one will not allowing gas cutting and leading.
I have found very few cases where I couldn't shoot over sized bullets (.001 -.002) without leading.

Then again I could just be full of it.

Michael

 

[GlockCop]

Well Another cause besides the ones you mentioned could also be too high of a velocity. In my early days of reloading I used to buy some cheap lead bullets(NOT J&K) and I got unbeleivable leading. It was a very soft lead. I wasnt going but about 750 fps. These were .38 wadcutters. It was so bad I had to buy a lead remover tool to get all the lead out of the barrel.

 

[Blitzfike]

One of the major causes of leading in a revolver is mismatch of bullet size to chamber throat in the cylinder. Undersize bullets do indeed cause more leading in my experience. Blitzfike

 

[MLR]

Well Another cause besides the ones you mentioned could also be too high of a velocity. In my early days of reloading I used to buy some cheap lead bullets(NOT J&K) and I got unbeleivable leading. It was a very soft lead. I wasnt going but about 750 fps. These were .38 wadcutters. It was so bad I had to buy a lead remover tool to get all the lead out of the barrel.

I fire soft bullets (30-1) alloy at well over 1200 fps with very little if any leading out of a rifle all the time. Cannot say what your problem but I would bet it is more than just soft lead at that low velocity.
Blitzfike hit on one very common problem with some makes of revolvers. The cylinder is incorrectly sized and swages the bullet down where it is undersized when it enters the barrel causing gas cutting and leading. There are cylinder hones that are made just for this problem. Unless a person slugs the barrel and if using a revolver he cannot really know what he is up against.

Also you can't always trust the size specified on the bad when buying bulk bullets. I took a mic to some bulk bags at a gun shop and found that their bullets were egg shaped. Measured .450 on one side then turned them a quarter turn where they measured .452. For my 44, if I try using bullets sized at .429 as is standard I get leading. When I size them a bit oversized with the same alloy the leading goes away.

Michael

 

[kd5rjz]

Soft lead causes leading. Excessive velocity with soft lead causes more leading. Fire a couple jacketed bullets and you'll remove most of said leading.

 

[gl89aw]

As is being discussed there are many reasons for leading, however if you do end up with lead in your barrel you don't have to spend a lot on a lead remover, just go to the grocery store and buy a pure copper scouring pad, may have to check out several stores, cut off a little of it and wrap it around your cleaning brush, usually takes the lead out in just a few strokes and won't hurt the barrel, sure beats wasting money on cleaners that claim to remove lead but do a really poor job with 10 - 20 times the effort

 

[Shadowrider]

Soft lead causes leading. Excessive velocity with soft lead causes more leading. Fire a couple jacketed bullets and you'll remove most of said leading.

I think that MLR was trying to emphasize that it's usually not soft lead that causes leading I.E. hard lead can "mask" problems by being a bit forgiving. Bullet to barrel fit is everything, take a good fit and you'd be amazed at how soft you can go without having issues. Take a look at Lyman's cast bullet handbook and you will see loads at 2200+ in rifles.

 

[Fyrtwuck]

Soft lead causes leading. Excessive velocity with soft lead causes more leading. Fire a couple jacketed bullets and you'll remove most of said leading.

There have also been discussions about shooting jacketed bullets in a leaded barrel causing it to blow up or bulge cause there was too much lead and it created an overpressure situation like a barrel obstruction.

 

[Jefpainthorse]

The jacket bullet trick...? I used to do that all the time and ended up spending a lot of time cleaning a SAA clone that was so leaded up that it started to keyhole bullets downrange.

The gilded bullets can press the lead into the grooves... it looks shiney enough but after a while ... they fill up with lead anyway.

 

[gaseous maximus]

I don't know if any thing I say is relevent, but when I started reloading cast bullets I ran them through a simple size die that I machined. I sized them to .357 and lubed with 1/2 beeswax & 1/2 paraffin, heated in a pan. bullets were 158 gr. Ray Thompson design without gas checks. Ran them "Max" over 2400, later Blue Dot. Launching mechs. Black Hawk 6 1/2 barrel & Virginian Dragoon 7 1/2 barrel. barrels leaded like crazy,( especially the ruger), 50 shots or so and the rifling wasn't visable from the forcing cone to 1/2 way or so up the barrel. So bad that I used mercury to remove. Later I went on to a harder alloy, tried to approximate the old lyman # 2 receipe. this helped a bunch but still got some leading. which brings me to Lee's liquid Alox. Since I have been using it, Leading for me has been totally eliminated (also I've been using an alloy of 10 lb. wheelweights, 10 lb. pure lead, and 1 lb pure antimony). even after several hundred rounds, a simple brushing, and 'Im good to go. this includes 38 spc, 357, 9mm, 45 colt, and 44 mag.The 357s for example (158 gr.) I am running at approx. 1450 fps out of the virginian, ( chronographed), this is over a surplus powder, the 124 gr. 9's at over 1100. Common belif was, years ago, that if a barrel leaded at the breech the bullets were soft, if it leaded toward the muzzle there was insufficient lube. Lastly, to anyone that reads this, please take a look at my name, and feel totally free to completely ignore my drivel.