Are Hard Cast Bullets Best

[J&S Custom Bullets]

Hi, I'd like to show every body an article about cast bullet alloys. It talks about whether or not cast bullets have to be as hard as most people make them, and does it hinder performance when they are.
http://www.sixguns.com/crew/obturation.htm

[cakes]

There is at least one obvious flaw in this "article". The soft alloy and the hard alloy were both sized to the same diameter and used the same lube. The hard alloy might have performed better if sized to a different diameter or if a different lube was used. Sounds like a sales driven "article".

[res45]

Say you have two identical bullets both sized to .358 dia. one is cast for straight WW alloy with a BHN hardness of say 10 and the other is cast from straight Linotype alloy with a BHN hardness of say 20+.

Both bullets are loaded in identical case,primer,powder charge. If the particular bullet is to hard for the pressure generated by the load used it want obturate enough to seal the bore properly and the harder bullet will actually shoot slower than the softer bullet that provides the correct seal to the bore although correct size is important it's not the only thing you have to consider.

There is a formula although I don't remember what it is exactly,but it's a number x BHN = pressure required to effectively cause the bullet to obturate properly. Thats why some commercial cast bullet maker offer different BHN bullets,the softer BHN bullets are designed to be shot at lower velocities and lower pressures that will generate enough pressure to cause the bullet to obturate,for higher velocities a harder bullet is needed to take the pressure created by the load,leading in not caused by friction as most people assume it caused by gas cutting or blowby. As the velocity and pressure goes up so should the bullet hardness.

Proper bullet size,hardness and lube all come into play. I shoot pure lead,in between and hard cast bullets in all my handguns semi and revolvers,leading has never been a problem as long as you match you bullet BHN,lube and load properly.

[J&S Custom Bullets]

Hi, I'd like to let every one know that the original article is at http://sixguns.com/crew/obturation.htm. And it was not written by me it was written by Glen E. Fryxell.

[cakes]

res45 explained it well.

[zb338]

I have been shooting cast bullets for years. The old formula has been
1 tin to 10 lead in automatic pistols and 1 tin to 20 in revolvers. That's
for mild target loads. In rifles you try to get hard lead and if you want
to shoot hotter loads you go to a gas check.

Zeke

[Popgunner]

Lasercast (Oregon Trail) bullets has a good manual for their hard-cast bullets that are 24 bhn. They state that their 24 bhn bullets obturate at 7,000 psi.
I read not too long ago about a test (I think it was Mike Venturino) where they removed the barrel from a revolver & just shot from the cylinder into water. Hard cast lead bullets were found to have expanded from .357 up to .45 caliber where there was no forcing cone or barrel to swage them down again.