Maximum hardness

[bronko220002]

What would you consider the maximum hardness for a full bore bullet?

 

[white eagle]

for what caliber?
I would cast differently for a 54 Smoker vs a 35 Whelen or a 358 Winchester
generally for big heavies I cast near pure lead BHN's and play around more with tin and antimony with rifle and handgun projectiles
Probably didn't answer your question but that is all I have at the time

 

[bronko220002]

strictly a full bore muzzleloader conical bullet

 

[HC]

This. To determine which alloy to use you have to decide what is the intended purpose of the bullet? And what caliber? And how heavy/long is the bullet?

If a gun is a 45 used for target, long range and is over 475 grains with a pointed bullet I would go 1-20 or even 1-16.

If the gun is a hunting rifle and bullets are 350 to 400 grains I would use 1-30 or about 8 to 9 BHN.

If the gun is a 50 and is for hunting. I would use 1-40 or in my case about 6 to 7 bhn.

 

[Ka'imiloa]

What would you consider the maximum hardness for a full bore bullet?

That's actually a very complex question, Bronko. Talking strictly muzzleloaders, what is your goal? Are you trying to stop gas-cutting of your bullet's base and

resultant leading in the rearward portion of your bore? Are you trying to negate possible nose-droop of your bullet during instantanteous obturation that occurs on firing before the bullet even moves? (Reference: "The Bullet's Flight from Powder to Target" by Dr. Franklin Mann, 1902.) Are you trying to penetrate the body and bones of an African or Asian elephant or an India Gaur, or even Yukon moose, large Bison, Cape Buffalo, Kodiak Bear, etc.? Are you pumping up velocity to achieve faster RPS (revolutions per second of your bullet), since more RPS is needed for longer bullets used in a given twist-rate barrel, as in 1000 yard shooting? Does your "full bore" bullet definition allow use of a paper-patch?

Thankfully, we are not limited like a cartridge shooter to a given length for both powder and wads, and can load bullet protective hard card, felt, Poly or other wads over our powder to protect the bullet base and negate gas cutting, no matter how long the powder column is. So that leaves us with the issue of bullet hardness versus the necessary amount of bullet bump-up (obturation) so that the bullet adequately grips the rifling lands and spins fast enough for stability to any given range.

Also, the heavier your powder charge, the more breech pressure is developed at firing, and this is increased as well as the weight of the projectile goes up. That means you theoretically want a harder bullet to withstand that increased pressure without gas cutting or excess deformation. It also means that you reach a point, with cast bullets, where they become impossible for the average person to swage the bullet to perfectly round, for ultimate accuracy and base-seal at firing. Even a sophisticated caster is going to have a hard time trying to swage a bullet at, and especially harder, than 1:20 tin-to-lead alloy.

Yet, for cartridge bullets, the early ones, such as Winchester's, were 1:16 alloy. That's not really very hard, but it helps the bullet keep it shape (for example, "flat-nosed"), as a better hunting bullet.

On the other hand, pure lead is the easiest to work with as far as achieving good obturation for optimum spin on the bullet via the rifling, but it also deforms badly when it strikes something, limiting penetration.

And for perfect bore fit, a paper-patched bullet of pure lead is great, because it will reliably expand at firing and split the patch so it leaves the bullet instantly at the muzzle. Works, but requires more care with muzzle-loading and a relatively clean bore. Good for target work, tricky for hunting.

This is generalized information for readers of this thread and others, but let us know what your goal is and maybe we can provide more specific info.

Aloha, Ka'imiloa

 

[bronko220002]

Well a gentleman on here wants me to cast a couple different bullets for elk in his .54 cals for him and his son. I advised him to use pure lead but he wants to try harder bullets for penetration and expansion for shoulder shots.
I told him if it were me I would use pure lead but would go to a 40:1 ratio lead/tin. He also asked for a 30:1 but I'm thinking that may be too hard without the ability to size the bullets to his bore(s).
I wouldn't want him to have a bullet stuck half way down the bore!

 

[snapbang]

If I was asking someone (you) to cast bullets for me, for a particular purpose, I would follow your advise.

 

[edmehlig]

My vote would be the 40-1.

 

[Saxtonyoung]

When I had my 45 caliber Omega I shot a lot of bullets from the Lyman 457193 mold that cast from wheel weights which has a brinell hardness of 12. In order to get decent accuracy I needed to shoot these with a 100gn of 777 2F. At 50 yards bullets would stack on top of each other but a 125 yards they opened up to 2- 3 inches. I found my first cold shot was always dead on. Probably shot more deer with this combination than with any other gun I used and never recovered a bullet with most shots being in the 100 yard range. So to answer your question you can cast hard bore size bullets but you will probably have to push them hard so they can fill the grooves to provide a good gas seal.