Water dropping vs alloying for hardness

[Jim Flinchbaugh]

So, I finally figured out by stiffening my alloy that I get better accuracy in one rifle of mine. Accomplished by water dropping range lead that had a BHN of 8.
Raised it to 16 by dropping in cold water. Is there any difference, as far as a hunting boolit is concerned, how the hardness is increased?
Does a water dropped boolit at bhn 16 remain any more malleable than say a blended Lyman #2 that isn't water dropped? I don't want to get brittle.
How hard is too hard for a huntin' boolit?

[runfiverun]

aha good question.
malleability is determined by the alloy itself, an alloy with little to no hardeners is going to be mashable and springy.
an alloy composed of just lead and antimony is pretty squishy if it's work softened.
[the antimony breaks down and allows the lead to slide easier but helps retain the structure of the alloy]
one composed of [a higher percentage of] tin and lead is a different story, the tin itself makes the alloy not so swageable.
now what does swaging have to do with the question you ask?
what happens to the boolit when it strikes the animal....
an alloy low in tin [tin is more of a grain refiner below .5%] and lower in antimony will of course be more malleable and flexable.
the water dropping precipitates the dendrites to the outside of the boolit because of the speed of cooling, you might also notice that it takes a month or so for a batch of water droped boolits to settle down and become a stable bhn.
the "harder" boolit still retains the malleability of the original alloy.
it all has to do with the "stuff' strung all throughout the inside of the lead holding it together, and what 'breaks" when it's bent and what merely gives or reforms.

it's like adding manganese, nickel, and carbon to iron instead of just carbon and nickel.

[btroj]

I like water dropped bullets for hunting. Good enough hardness to drive them to the speed I want yet the alloy is low enough in antimony to expand without being brittle.

You just discovered why hardness alone doesn't tell the whole picture. One hardness can be achieved by many means. Each alloy with that hardness can still behave in a very different manner in the barrel and on target.

[fredj338]

I believe water dropping hardens the surface while alloy hardening is uniform throughout. For hunting, I would think water dropping preferable.

[Clay M]

I just cast some .45/70 bullets for hunting. I used a mixture of 80% WW and 20% Lino. I let them air cool.Should know how they work on deer soon.I am using a gas check and Carnauba Red lube. Pushing to around 1700fps with no trace of lead.

[btroj]

Those are some hard bullets, they aren't gonna expand at all. Wouldn't want a HP with that alloy, it would fracture and blow off.

My 45-70 bullets for similar velocity are more likely to be range scrap with a little mag shot added then water dropped. 45-70 just doesn't need a real hard bullet.

Again though, hardness is only one measure of how a bullet will behave. It often isn't the most important.

[Clay M]

I have killed a ton of deer with air cooled WW and none of the bullets expand unless I hit a bone.These bullets aren't brittle like pure Lino.All the deer run about 80 yds whether I shoot them with a 400 gr Speer bullet or cast.That is unless I break both front shoulders ,then they go down right there.A neck shot is also good.

[oldandslow]

Jim, 11/2/13

I've been casting and reloading for a number of rifles and shotguns and trying different alloys (tin, antimony, copper) and different heat treating processes (70 degree or ice water dropping post heating to 465 degrees for 60 minutes). Since I use the rifles for pig hunting I want the boolit to retain as much of its weight as possible. This means that I had to find some way of recovering the boolits and weighing them for percentage of retained weight and deformity. What worked for me was water-soaked paperback books from the Salvation Army. Most boolits penetrated 16-19 inches. Weight retention depended not only on the alloy but also on the velocity. The very hard (BHN) alloys often suffered marked weight loss due to fragmenting. Same for boolits run too fast (about 2200 ft/second) when the boolits started fragmenting before hitting the target as the nose twisted off the bases. This occurred more often with the rapid twist rifles (1:7 and 1:10 twist) than the slower twist ones (1:12).

So in summary you have a number of factors influencing accuracy and toughness for a hunting boolit (alloy, heat treating temperature and water temperature, barrel twist rate, velocity) along with the usual factors like boolit design, weight, fit-to-bore, lube, etc. Keeping detailed notes and then referring back to them often leads to new ideas to try. Good luck.

best wishes- oldandslow

[paborn]

Ductility is a solid material's ability to deform under tensile stress. Malleability, a similar property, is a material's ability to deform under compressive stress. For hunting with an expanding bullet, what we want is the optimum degree of expansion at a given velocity. To get that optimum with a malleable alloy the hardness has to increase as velocity increases.

For lead/tin/antimony alloys, the best malleability is achieved with equal percentages of tin and antimony, as they form an intermetallic compound is soluble in lead (it is no accident that Lyman #2 is 90/5/5). 98/1/1 makes an excellent alloy for handguns at 900fps, 90/5/5 makes an excellent alloy for rifles at up to 2000 fps. Heat treat softer alloys to act like harder alloys. Heat treated ww with 2-3 percent tin can be driven to 2400fps in my rifles, with all other variables correct.

Paborn

[GARD72977]

I have read that a water dropped bullet will loose the hardness if it is sized because you work the lead. Is there any truth to that?

[Clay M]

I have read that a water dropped bullet will loose the hardness if it is sized because you work the lead. Is there any truth to that?

That would be easy enough to check with a hardness tester.

[Jim Flinchbaugh]

I have read that a water dropped bullet will loose the hardness if it is sized because you work the lead. Is there any truth to that?

my limited experience is no.
I've water dropped, tested bhn, then sized, filed the luvern rings flat to test again and it was the same hardness as the untouched nose was.
Whether or not this changes as the boolits sit over time I do not know, most of mine dont sit long enough to find out :D

[zomby woof]

It seems to me, accuracy wise, that an air cooled alloy say #2 shoots better than a softer alloy water cooled to the same hardness. That is in a rifle. That is what I'm experiencing.