doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Heat Treated Lead Shot?

A fair number of years ago, I experimented with heat treating some "butter shot" lead #4 shot that was nicely round but so soft that one could compress the pellets easily with two fingers with a pliers. The following technique was based on what I remember to be a piece in the American Rifleman [though the folks there can't seem to locate it, now]

I heated the shot to about 425 degrees F in an oven for about 30 minutes. Then, I quickly quenched the hot shot in a bucket of cold water.

The water took on a black "slick" as the shot's graphite coating floated away.The treated shot looked just awful; gray and rough to the touch though it was still nicely round.

When I did "the pliers test", again, I found that I could not compress the shot even when I bore down with two hands. The best I could do was to scratch the surface of the pellets, slightly.

Lacking graphite, I sprayed WD-40 into the shot and then hand mixed the shot until all of the pellets were nicely, but not excessively, lubricated.

The following weekend I gave the shot back to its owner to load in his Damascus-barreled Parker 10-gauge double. He loaded the shot in a black powder load that was, as best that I can recall, something like 3 1/4 drams of Goex FFg x 1 1/4 ounces of shot in a Remington plastic hull with a Remington plastic wad. I never found out what primer he used.

The results were amazing. The weekend before the man gave me the shot, he had trouble obtaining any better than Skeet choke patterns with his gun's full choke barrels. With the hardened shot, the gun patterned in the 90s per cent at 40 yards. I could almost claim 100 per cent patterns but the man did not count his pellets before he loaded them. However, if there were any "fliers" outside the 30-inch circle neither he nor I nor any of the other people present could find any. Patterns were nicely-distributed, too.

Has anyone else ever tried this technique?

DISCLAIMER: This test was run before current concerns about lead vapor contamination existed. I am not sure that I would "cook" lead projectiles in an oven that was to be used to bake food, today.

Dingelfutz;
I have not tried this. I do recall some articles in the AR concerning heat treating cast rifle bullets. The process was essentially the same as you describe for the shot. It is necessary I believe for the lead to have some % of antimony for this to work, I don't believe it will harden pure lead. In the article I seem to recall bullets cast from wheel wt metal was given a hardness very similar to linotype. Some of these articles appear in the AR cast bullet handbook, but I do not know if this is still in print or not.

hit wid da torch...

Thanks, guys.

Geno, this is an excellent article. It reflects E. H. Harrison's tests 1970's tests closely. I will try to look up 2-Piper's reference, too.

I would still like to find out whether anyone else has done this with shot. I am especially interested to find out whether different shot sizes have any bearing on "hardenability" or hardness decay over time.

I was operating purely on memory on my references, but I believe most of those I cited were the work of E H Harrison. At least he did a lot of the articles in that NRA Cast Bullet Handbook. They were all scattered out over several years, but assembled together in the habdbook.

Isn't that the same as chilled shot?

No, "chilled" only means that there is an antimony content significent enough to increase hardness noticably. "Magnum" grade usually has significant antimony and tin content for "maximum" hardness and sphericity.

Way back when as I understand it, there were generally two classes of shot known as Drop & Chilled. R'Man can likely correct any inaccuracies here. Essentially they were both made by an identical process. The shot was poured through a vibrating sieve from atop a tower & caught in a large vat of water. So in effect both were "Dropped" & both "Chilled". The difference was as R'Man stated the amount of hardening alloy content of the lead. As I understand it the fall of the shot through the air allowed it to cool sufficently & the water in the vat quickly became heated to the point the "Heat Treating" affect didn't take place.
The Magnum shot would come along at a later date with a still higher alloy content than the Chilled.

There's a lot about shot making I have never understood, but would like to.

A friend has a Littleton shot maker, and in the instructions it says to add something to the water in the drop vat to help increase maximum roundness. As I recall, one of the additives suggested is a type of water soluble oil, or crop oil, as is sold for an agricultural pesticide spraying additive. This is for shot dropped from only tabletop height into the water.

Why is shot dropped from the top of a tower, as I always read it is, if it is only necessary to drop it a few feet to maximize roundness? Or, is the minimal fall that is recommended by the Littleton folks just for convenience sake, understanding that the shot resulting will not be as perfectly round?

Maybe someone here has had experience with the Littleton that they could share?

SRH