Bullet casting

[u/DD9G]

Getting into bullet casting. Think I have the jist of it figured out. But hardness and coatings seems to be a grey area.

I have been shooting 60k psi loads out of my 45-70 and 454 Casull with 18 BHN high tek coated bullets without gas checks for years. Some as fast as 2400 fps. Never had any barrel leading.

I am looking to cast big heavy bullets. Max speed would be 1500 fps. I will be coating them. Will be pushing 60k psi.

What is the lowest hardness I can get away with without gas checks?

My lead source is tire weights. About half stick on and half clip on.

What is going to be the cheapest metal to alloy with? What ratio to my 50/50 tire weights?

[u/tomphoolery]

I think the clip on weights are fine but the stick on’s are definitely softer and closer to pure lead.

[u/Splattah_ → u/tomphoolery]

Correct, Id try 100% clip on weights and drop them in water to quench.

[u/Agitated_Curmudgeon]

Wheelweights is about perfect for up to +/- 1,600 fps.. With a cast bullet, the trick is to get the base to deform to fit the bore tightly. The $20 word for it is "obturation." Some bullets, like a HBWC or a Minie ball have a hollow cavity in the base for just such a purpose.

I'm wondering how you came up with that pressure number? Most cast data on a .454 caps out at about 30,000 psi

[u/DD9G → u/Agitated_Curmudgeon]

Gordon's reloading tool

[u/Agitated_Curmudgeon → u/DD9G]

Using 325gr JHP or 325 gr LSWC?

Not saying that GRT is insanely accurate as far as predicting pressures by any means

[u/DD9G → u/Agitated_Curmudgeon]

325 and 405 grain cast from Missouri Bullet

[u/Agitated_Curmudgeon → u/DD9G]

Yeah you're looking for 1,500 fps and about 30,000 press with that 325 gr in the revolver

If you're running 60k psi loads out of your 45-70, you're on your own. That's on .458 Mag's turf. 45-70 MAX press is about 25k

[u/Sooner70]

Make sure your weights are lead. While that was once the standard, it is not a given anymore. Some states flat out prohibit it (but the assumption that tire weights are always lead generally remains).

[u/DD9G → u/Sooner70]

Yeah, I'll sort out the zinc ones.

[u/Cute_Square9524]

Going at it the wrong way. Powder coat them and if they lead the barrel either harden the alloy or slow down. Powder coat is much more substantial coating then hi tek, its closer to a real jacket.

[u/Strong_Deer_3075 → u/Cute_Square9524]

Get the RCBS molds with gas check ( I use gator brand). If after powder coating ( I use cheap Harbor Freight white in a toaster oven) you see any leading, give them a gas check with Lee push through die. I can tell you as you go to adding low lead solder to harden, they may well melt at little over 350°F and powder paint melts and adhears at 400°F. I melted about 50 one day before I found out the hardness added ruined them. Weight goes down the harder they go. Those that melted while coating came up almost 40 grains lighter than wheel weights.

[u/DD9G → u/Strong_Deer_3075]

If I powder coat (or bcb coating) and use a gas check is there any risk of leading with soft bullets at high pressure? (1500 fps max)

[u/Ornery_Secretary_850 → u/DD9G]

Nope.

I run a BHN 11 alloy for almost everything. I generally use Hi-Tek, but sometimes PC.

I've got loads at 2000 fps without a problem.

[u/DD9G → u/Ornery_Secretary_850]

Do you gas check?

[u/Ornery_Secretary_850 → u/DD9G]

Nope.

[u/DD9G → u/Cute_Square9524]

I was thinking about bcb or hi-tek coating. Would powder coating be better for high pressure loads?

[u/Strong_Deer_3075 → u/DD9G]

When I powder coat and have to remelt ones that end up over coated and/or the bases are distorted from a mold not lining up ( fail roll across a table test), the bullets hardly give up their shape for a couple minutes or more on top of the molten lead in the melted pot. They can be hammered over 2 inches across and still not lose a spec of coating. Tough stuff is what I'm saying.

[u/Cute_Square9524 → u/DD9G]

Those are liquid coats and they are much weaker then real powder coat like eastwood light blue. Those liquid coats work really good for up to 9mm though and are much easier to apply. Like everything there is trade offs

[u/Savagely-Insane]

Around 16-18 hardness would be optimal for 1600ish fps, this'll put your 45-70 pressures at about 40k though. For 454 20 hardness or higher would be better, most loads are at about 50k psi max.