how fast it too fast for lead?

[dmrodco]

I am loading 40SW with hardcast lead. my question is without gas checks how fast is too fast for lead? thanks in advance for your replys.

 

[Steve C]

It depends. Not the answer you wanted to hear exactly. The factors that affect how much velocity you can get or need to have to avoid leading depends upon the bullet hardness, the bullet lube used, the type of barrel and how clean and how smooth it is, powder used and a host of other items related to the size of the bore and bullet.

In my experience:

Polygonal barrel like Glock and HK factory barrels lead at all velocities, don’t even bother using lead in the these barrels.

Softer swaged bullets begin leading around 900 to 1000 fps.

Hard Cast bullets can be pushed as fast as jacketed and often need to be pushed that fast as they actually will lead at low velocity and not at the higher pressure higher velocity. The hard waxy lube they use isn’t the best and a light coating of Liquid Alox added over the commercial lube will eliminate a lot of the leading problems.

A dirty barrel including those with copper fouling will lead where a clean barrel often will not depending upon the other factors.

A new pistol barrel that hasn’t been shot enough to smooth it out will foul when a well used barrel doesn’t.

 

[BeJaRa]

I generally try to keep my lead loads under 1000 fps but I also only load 45 ACP and 38sp with lead.

 

[Uncle Don]

I use wheel weight lead and then coat them with liquid alox. I have a rifle that I've chronographed at slightly over 1700 fps and after about 400 rounds, don't have any leading.

 

[dmrodco]

Thanks steve those are exactly the issue I wanted to hear about GREAT info !

 

[NuJudge]

Some more thoughts

If you buy cast or swaged Lead bullets, you do not have control of many factors. There are at least two more conditions Lead bullet buyers can control that can prevent a lot of Leading, one is avoiding using undersized bullets. Gasses blowing past the bullet will cut significant amounts of Lead off the sides of the bullet, and deposit it in the bore. Groove diameter varies between barrels, especially in older firearms. It would be good to slug your barrel to find groove diameter.

It would be nice for Lead bullets to be slightly larger than groove diameter for your barrel. This would cause faster sealing of the throat just ahead of the chamber. I cast/lube/size to .001" or .002" larger diameter, and I cast them hard. Some people like to use soft bullets and very fast powders, hoping that if the bullets are at or a little small for groove diameter, they will "slug up" to whatever diameter is required (this has not worked for me, except with dead soft bullets and black powder in muzzleloaders).

In semi-autos, the cast bullet you need, when seated in the case, may increase the diameter of the cartridge to the point where you do not have free chambering of the cartridge. The only thing you can do then is use jacketed bullets. Gas blow-by with a small bullet does not remove significant amounts of jacket material.

Buying a heavy Lead bullet will mean your velocity will be lower, which also reduces the likelyhood of Leading.