Home Forums Reloading Bullet Casting Alloy Hardness

Those that mess with concocting your own alloy, how do you test the hardness?

Reason I'm asking:
I'm no expert bullet caster by any measure, but I'd like to be. I don't own any kind of hardness tester.

I have a good supply of "pure lead" that casts a nice roundball for the flintlock, that engraves perfectly on a patch.

I used to have 500 lbs of "linotype". I helped smelt down the many boxes of letter blocks obtained from the basement a local newspaper. My since deceased old gunsmith buddy said it was legit stuff and we were supposed to split it, but I ended up in possession of it all. I've since given some away but still probably have 450 lbs left, and been saving it for dark and gloomy days.

In the middle I hoarded wheel weights back in the 80s and 90s and have probably 300 lbs stashed. It's probably a potpourrie of who knows what throughout the entire lot. I've cast some plinker pistol bullets with it and my one son is using it in his cap & ball revolver with the 45LC conversion cylinder.

I'd like to start using this wheelweight stuff in a couple project rifles in a serious sense, and want to maintain a consistent alloy. So knowing hardness would be a big help in that should I need to tweak it one way or the other.

I have an old LBT tester, but Veral Smith's shop burned down and the testers are no more. If I were looking for one now I would probably go with the Cabin Tree model.

Quite the trove of lead! I would start scrounging as much dead soft lead (as pure as possible) to mix with the type metal and/or wheel weights. Either one alone is rather harder than needed for even rifle bullets pushing close to 2000fps. A little type metal goes a looooong way. Once you have a pile of soft lead gathered up, then I would sit down and consult charts that abound for the purpose of making "X" alloy from known additives. The trick is to do as big a batch as possible to achieve consistency in subsequent casting sessions.

Might be worth while to start sorting those wheel weights now too. If they're newer then you'll likely find three varieties: clip-on style lead (the all time standard for this work), stick-on lead which are awfully soft maybe pure lead (useful in their own right), and the dreaded clip-on zinc types. Sh*t can the zinc ones and take great pains not to allow any to end up in the lead pot. With a little practice you can identify them. Basically they're harder than the lead clip-ons and that's how guys separate them (use your imagination).

I've borrowed lead testers in various price ranges, done the ball indent formula, and after all that I keep going back to lead hardness testing with quality drawing pencil sets. Go to a search on the subject or better just go to Cast Boolits, where they have a complete description of the process with lots of tips.
later edit...the best one I have is a Mars Lumograph, 12 pencil set in a metal box, made by Staedtler in Germany. Maybe was about 14 bucks on ebay?

gnoahhh,


Already sorted the wheelweights a couple decades ago and melted everything down into ingots. They were all clip on weights from before stick on became much of a thing and the changeover to zinc.

I'll check in that, thanks.

I can't emphasize enough, what Gnoahhh said above about bullet hardness above. Bullets that are soft enough to obturate to seal gases are the key to success. I don't know why, but mass producers are still beating the drum and using the term "hardcast" as if it was a good thing. It never has been a good thing IMO. As a matter of fact I will go so far as to say, the much ballyhooed standard of Lyman #2, around 15 is harder than needed 75% of the time. Here is a simple formula for guesstimation of pressure needed to deform a given hardness of bullet, (BHN) X 1422= PSI...this will get you in the ballpark and keep you out of the leading zone, assuming you have some idea of the PSI of your load.
If you want to go a different direction, you can use about any hardness, IF! your bullet perfectly seals the throat. Of course, the newer powder coating covers so many sins of hardness and fit that it should have been called blanket amnesty, or so I'm told, having never fired a single one...yet.

Thanks for that info, I'm sure it will be useful. "What hardness?" was going to be my next question in a series of questions on this.

I won't be powder coating anything. This is old school from beginning to end.

What cartridges will you be casting for and what velocity levels are your aim?

I've pretty much switched completely over to simple binary alloys, tin/lead - 1:20 for simple old school revolver bullets and low-vel rifle stuff, 1:15 for .45ACP, and 1:10 for rifle stuff 1400-1800fps. I have a monstrous amount of WW, linotype, and monotype gathering dust, but it ain't going anywhere.

The first project rifle is my 1958 Marlin 35 Rem with a 200 gr FN, the second project is my 2016 Remlin 45/70 with a 405 grain FN which I still need to source the mold for. There may be a 3rd Marlin rifle at some point in 375 Win that will be primarily for jacketed loads but I'll find a good mold just in case i decide to use cast in it. That one still needs to go to JES for a rebore from 30-30.

I'll probably want all three on the same diet of alloy. No?

As far as velocity let's marry a good alloy with an appropriate velocity to use these rifles in the hardwoods breaking the front running gear on whitetails, out to 100ish yards if the accuracy is there. That'll be their primary use other than just having some fun stuff to shoot off season.

Straight wheel weights or similar alloy will work for your rifles. The marlin 35 rem will probably have a very short or non existant throat, so be aware that any cast bullets for it will probably be into the rifling. I have the RCBS gas checked moulds for my 35 Rem, 38-55 and 45-70. They work very well.

We are throwing a lot on your plate at one time. But examples are easy, let's take your .35 Rem, Lyman Cast manual 4th edition (current I think). Most of the published max loads run around 30,000 CUP, let's convert to psi... (1.516X 30,000)minus 17,902=27,578 psi. Then dividing 27,580 psi by 1422...we come up with roughly 19 Bhn for max loads in the .35Rem. But, IMO I think you will find happiness down in 15k-20k pressure and 1400-1500 fps...but I've never hunted a .35R.
Because the formulas call for a 19 BHN for max loads...don't take that as gospel, I have friends using wheelweights with gas checks at 2000 fps in the Krag and Lee Enfield with great success.
Avoid pointy mold styles, go with moderate velocity and nice flat meplats....thwock, meat in the pot. IMO, Your old .45-70 will become your favorite, I'd bet. I have 3 .45-70's, 2 trapdoors and a Ballard Pacific....the worst carbine can do 3" 5 shot groups at a 100yds. Plain ol' 405 Lee mold.

Certainly no harder than wheelweights with a pinch of tin to aid mold fillout. Personally I would go even softer because none of them are particularly hot screamers, say 50/50 WW/lead - I would load a box and see how they shoot and make sure they don't lead the bore. If poor performance is the result I would switch up to 75/25 WW/lead. Still add a pinch of tin for fillout.

It's been so long since I sweetened soft lead with type metal that I don't remember the proportions. I would have to consult the charts. Maybe 75/25 lead/type metal sticks in my mind. Remember, any time you alloy with type metal the hardness will shift a bit harder with age. A bullet composed of a lot of type metal that registers, say, 15bhn out of the mold will harden a couple points after a couple weeks.

Wheelweights with a "pinch of tin" will expand reliably on game at somewhat sub-2000fps, but as you know bullet shape has a lot to do with it too. This one was a .30 190 FN cast of WW+tin, at about 100 yards, muzzle velocity 1900 fps , .303 Savage. .308 bore, .310 throat, sized .310"

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Let me get past my daughter's wedding this next weekend and the next couple months of deer season and then we'll have some breathing room to do a deep dive on this where i can put my mind right to it. I certainly appreciate everything so far!!!

This^^, that's what I use. Get a quality German pencil set and read the procedure on Cast Bullets. There are also YouTube videos on the subject.

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Thank you DigitalDan