Leading
As a toolmaker, I would say you could probably heat a gun barrel to 200 degrees without damage, but it wouldn't help much with lead removal.
The Chore Boy pads work well, as well as the Kleenbore Lead Removal
cloth. The cloth requires a very tight fit in the bore to remove lead
quickly, though. A Lewis Lead Remover kit is the Cadillac.
As a long-time bullet caster, I can testify to the fact the general consensus of harder bullet, lower velocity is flawed. You can make a bullet TOO
hard, and it will lead much worse than even a swaged lead bullet.
Harder bullets are required for higher velocities only in that they need the
hardness in order to purchase the rifling and prevent skidding, which
destroys any hope of accuracy. Lead deposits don't come from friction.
They come from the high-pressure gasses flame cutting the bullet, and
getting past it in the bore. The result is much like a soldering operation,
and the higher the tin content, the more durable the solder, and the more stubborn it is to remove. As the deposit builds up, it slows the passing of the bullet, and gives the flame more time to melt the sides of the bullet.
A perfect example is that 234 grain bullets cast from wheelweight metal
lead badly in .45 ACP at 850 fps. Bullets cast from that same batch of alloy into 160 grain SWCs, and driven to 1300+fps in a .357 magnum
don't lead at all beyond a little lead wash, which comes out easily with
a brush and Hoppe's #9.
The higher pressures cause the base of the bullet to upset and seal
the bore tightly, preventing gas cutting, and leading isn't a problem.
By contrast, a soft, swaged lead bullet doesn't lead nearly as badly in
a low-pressure round like .45 and standard .38 Special loadings
because the softer metal upsets easier than the harder alloy.
Low pressure/low velocity loads would probably do fine with alloys
of 90/10 solder with no antimony, but the problem is that without
antimony present, the mold either wouldn't fill out properly, or it
would drop a bullet that was undersized...which would allow
flame cutting before it had time to seal the bore. Antimony has a
property that is like water. It expands as it solidifies. Straight
lead/tin doesn't, though the high tin content does aid in filling out
the mold. It needs at least 1% antimony to give the bullet that
final "swelling"...and in some guns with groove diameters that are
on the high side of tolerance, it may not be enough.
I have nearly eliminated leading in .45 ACP by using a home-brewed alloy
of 97% lead/2% tin/1% antimony by weight. It can get to be a little
expensive, though. The simplest way to get the antimony is to use
Lawrence brand #8 shot, which is 7% antimony, Dutch Boy 50/50
rope solder, and lead sheathing, which is about 99.5% pure lead.
Straight wheelweight alloy with a little tin added makes for accurate,
non-leading bullets for the magnum revolver cartridges, as long as they
are pushed hard.
Just a little info from a lifelong caster...
Tuner
