What is the best way to harden cast boolits?

[Cobretti]

I am new at casting and I am still in the process of purchasing all the equipment. I've read about cast bullets needing to be hard. I am smelting wheel weights. Is there something else I should add to make the alloy harder? Does heat treating them work or dropping them in cold water after casting? Thank you for your input.

[jmort]

Spend a few weeks reading all the stickies on this site and Lyman's Cast Bullet Manual and the all the articles in the link below from the LASC Cast Bullet Notes link at bottom of page. Sometimes you MAY want a "hard" boolit and most of the time not. If I needed hard Boolits I would heat treat a 93/3/3 alloy but most would think that is a waste of tin, not me, that would be the best possible alloy in my opinion for hunting/self-defense either heat treated or not depending on a lot of factors that are discussed in the stickies, threads, manuals, links, etc., etc. take some time and enjoy the learning process. One thread and a few posts will not get you where you need to be. I would not spend a dime until I put in some serious time educating myself.

[454PB]

I don't know if it's the "best" way, but heat treating is probably the cheapest way. If you drop the boolits from the mould into cold water, within a week or so they will increase in hardness by 25% on up. Just be aware, they have to be sized shortly after casting.

[Larry Gibson]

Water quenching out of the mould is the fastest and cheapest way to harden cast bullets. A good alloy for hardening is also needed.

Larry Gibson

[gray wolf]

For your edification and long term knowledge base this is the best advise anyone could give you.
It could also be fun to learn something new, well actually you will learn a lot.


Spend a few weeks reading all the stickies on this site and Lyman's Cast Bullet Manual and the all the articles in the link below from the LASC Cast Bullet Notes link at bottom of page. Sometimes you MAY want a "hard" boolit and most of the time not. If I needed hard Boolits I would heat treat a 93/3/3 alloy but most would think that is a waste of tin, not me, that would be the best possible alloy in my opinion for hunting/self-defense either heat treated or not depending on a lot of factors that are discussed in the stickies, threads, manuals, links, etc., etc. take some time and enjoy the learning process. One thread and a few posts will not get you where you need to be. I would not spend a dime until I put in some serious time educating myself.

[osteodoc08]

You must have arsenic present for it to harden as well. It's already in the COWW and Magnum shot.

Drop from mold into water or use the oven. Both are well covered.

Your COWW are good for most applications. "Hard" bullets tend to be over rated.

[454PB]

You must have arsenic present for it to harden as well. It's already in the COWW and Magnum shot.

Drop from mold into water or use the oven. Both are well covered.

Your COWW are good for most applications. "Hard" bullets tend to be over rated.

Arsenic improves the process, but is not required. Antimony is the required ingredient.

[Cobretti]

Thanks guys I'll keep reading up on things. It's still freezing cold outside so I won't be casting any time soon. If I have any other questions ill be sure to ask everyone's opinions.

[Cobretti]

I don't know if it's the "best" way, but heat treating is probably the cheapest way. If you drop the boolits from the mould into cold water, within a week or so they will increase in hardness by 25% on up. Just be aware, they have to be sized shortly after casting.

454PB,
How soon after casting do they need to be sized? I just got a Lyman 4500 Lube Sizer.

[btroj]

Water quenching out of the mould is the fastest and cheapest way to harden cast bullets. A good alloy for hardening is also needed.

Larry Gibson


This is true.

Want a really hard bullet? Put a jacket on it......

[Cobretti]

Is is true.

Want a really hard bullet? Put a jacket on it......

I read a thread that said harder cast rifle boolits are more accurate at a longer distance. True ? I plan on starting with pistol calibers and then go on to rifle calibers when I have more experience.

[osteodoc08]

Arsenic improves the process, but is not required. Antimony is the required ingredient.

While I don't disagree with your statement (it is a true and factual statement), I've always been under the impression, that As is needed to achieve the levels of hardening associated with water quenching and that water quenching a non As alloy is virtually pointless. Perhaps I'm wrong. I look to the collective knowledge here as I'm always learning. You can shoot a super hard high antimony boolit, but is quite fragile from a malleability standpoint.

Not trying to be argumentative at all, just trying to understand I guess.

From "From Ingots to Targets"
In addition, arsenic (As) is commonly added to industrial lead-tin- antimony alloys to improve the strength (this strength enhancement is only observed when As is added to a Sb containing alloy, As is virtually worthless in the absence of Sb). Arsenic also significantly enhances the ability of the alloy to be hardened via heat treatment. All that is needed is 0.1% (more does no good). Wheelweight alloy commonly contains about 0.17% As.

[longbow]

It all depends on usage ~ required terminal ballistics, rifling twist, velocity, pressure/acceleration and likely more than a few other things.

If you want to use the boolits for hunting you may want a hard alloy with large flat nose for penetration and tissue damage or you may want a softer alloy to provide expansion.

If you are plinking and punching paper then alloy hardness is not important as long as accuracy is good and you don't get leading.

If you want to shoot looooong range so have to squeeze out as much velocity as you can to flatten trajectory then a hard alloy may be required.

I found that with 200+ gr. boolits in my 1:10" twist Lee Enfield I was getting some swaging of the boolits if they were ACWW ~ the rotational acceleration with that load was causing the skidding. After oven heat treating the problem went away. Never had that problem in slower twist barrels.

Boolit fit is first and foremost so once you are set up, slug your bores and throats so you know what you have then size boolits to suit the gun. Usually 0.001" to 0.002" over groove diameter or as large as will chamber and fit into the throat are reasonable guidelines for fit. I tend to size to suit the throats in my guns.

Lots of stuff to consider and learn along the way. I know I am still learning after about 45 years of casting boolits.

As stated, do some reading and ask lots of questions if you have them. No sense in wasting time making the same mistakes many of us have (I know I have made a few!).

And welcome to the forum.

Longbow

[357shooter]

I read a thread that said harder cast rifle boolits are more accurate at a longer distance. True ? I plan on starting with pistol calibers and then go on to rifle calibers when I have more experience.I agree with the others. There are a lot of assumptions that for your rifle, caliber and load that harder than WW is more accurate. That's not neccessarily true. What are you planning on doing (hunt, silhoutte, plink), what range are you thinkinga about, caliber and type of rifle. Gas check or plain base is another question.

[DRNurse1]

Thanks guys I'll keep reading up on things. It's still freezing cold outside so I won't be casting any time soon. If I have any other questions ill be sure to ask everyone's opinions.

Good choice. Two things I missed about hardening on the first couple of go rounds:

1--All cast boolits age harden to some extent. The trick is to balance your supply of alloy and your need for 'hard' boolits.
2--"Hard" is a relative term. Read up on the history of the boolits and the lead balls were around 5.5 BHN [Brinell Hardness Number] then were supplanted by 'hard' boolits around 10-12 BHN. If you need more than 12-14 BHN for your boolits to function in your particular gun, you may need to water drop or heat treat them.

So knowing the alloy(s) you have to start helps, then learning how to get the right alloy for your needs is probably next, then probably have to figure out how to mix stuff into your basic alloy to get the hardness you desire. Of course, you could just cast and shoot what you have, then trouble shoot the results, which probably would be easiest to start.

Just my $0.02 and I am no where near the top half of the knowledge bucket here.

[Cobretti]

I agree with the others. There are a lot of assumptions that for your rifle, caliber and load that harder than WW is more accurate. That's not neccessarily true. What are you planning on doing (hunt, silhoutte, plink), what range are you thinkinga about, caliber and type of rifle. Gas check or plain base is another question.

I was thinking .308 with a gas check out to 200 yards just plinking. If they were accurate enough I wouldn't mind using them for hunting if possible.

[454PB]

One of my favorite alloys is 30% linotype and 70% pure lead. When water dropped, the boolits will harden to 22 to 24 BHN in about two weeks. Though I've never done an analysis of linotype, I'm not aware of any arsenic.

I size water quenched boolits within a few hours. If you wait even one day, they will have hardened enough to make sizing difficult, and sizing reverses the hardening process.

[357shooter]

I was thinking .308 with a gas check out to 200 yards just plinking. If they were accurate enough I wouldn't mind using them for hunting if possible.
You might try 16 grains of 2400 under a checked WW bullet.

[bangerjim]

I can get alloy mixes WITHOUT water dropping of 15-22bhn by just using the correct alloys in the mix. I never rely on water dropping for gained hardness. If I water dropped my hardball alloy, it hits over 33bhn! I powder coat everything which minimizes the concern for "worryingly about hardness".

To water drop you need antimony not arsenic.

If that process is new to you, please read the stickies about powder coating. Very successful with many many on here!

bangerjim

[prs]

Arsenic IS a definite important factor, sort of a synergistic catalyst in the process; BUT is only required as a trace element and is so commonly found in lead and lead alloys as at least a trace that we really don't have to worry about it much. Use a bit of magnum shot if you absolutely get that warm and fuzzy feeling knowing for sure there is at least a trace of arsenic.

If water dropping, I suggest you select a mold that drops close to your desired final size to begin with; then if you still need to size or lube size, do so immediately after casting session or as soon as practical. They will be significantly harder from the get-go and will age harden more as time goes by up to a several weeks. If your mold drops to size, you lube in a die a thou or two larger and thus disturb the hardening process less. Unless you are mass producing, you may desire to read-up on oven treating/then quenching by the batch after sizing and before lubing in a slightly larger die. BUT, bullet fit is as important or more important than hardness and lube quality is another biggie to recognize. Save yourself some grief and barrel de-leading effort by reading as directed way up above in this thread.

Happy experimenting!

prs

[mdi]

A lot of good info has been presented, and I'd just like to add one small fact; Most new casters are caught up in the "harder is better" old wives' tale. Ain't necessarily so. To further feed the tale/misinformation, commercial casters provide "hard cast" bullets, 18 BHN and up (but I believe it's mostly for shipping/handling so the bullets don't get dinged up). As far as I can remember the term "hard cast" was used only to differentiate between cast (regardless of BHN) and swaged bullets. The term has been used for all cast bullets so much that many new casters believe that cast bullets must be hard for good accuracy and low/no leading.

I have only been casting about 17 years and very rarely cast anything harder than wheel weight alloy, which can vary from 9 or ten to 12 BHN. I started casting for my .44 Magnums and have run plain based, my alloy, bullets to 1300 fps (my guess) so I guess the "1200 fps limit" don't apply to my casting...

[MtGun44]

"I read a thread that said harder cast rifle boolits are more accurate at a longer distance. True ?"

Not necessarily connected. IME you can get excellent accuracy from 8 BHN to 12 BHN (Range lead
to wwt alloy) with any of the regular magnum pistol cartridges. For rifles, you may need harder
alloy or heat treating. I don't load hot loads in rifles, only the 16 gr or 2400 or 10 gr Unique range
except for one .45-70 load and none are anything harder than air cooled wheelwts about 12 BHN.

Hardness is WAY overrated. Fit is FAR more important, lube quality and boolit design usually overshadow
hardness, too.

Very hot .45 Colt "magnum" load, air cooled wwts:

http://castboolits.gunloads.com/attachment.php?attachmentid=52429&d=1307309022

Hot .357 Mag load, range lead at 8 BHN:

http://castboolits.gunloads.com/attachment.php?attachmentid=50446&d=1244513448

Bill

[243winxb]

Add Linotype, the antimony makes bullets harder & larger in diameter as they drop from the mold. http://i338.photobucket.com/albums/n420/joe1944usa/Firearms%20%20and%20%20Reloading/AlloyBlending1.jpg http://www.photobucket.com/joe1944usa