Hardness test Heat Treating

[BulletFactory]

This is a mystery alloy, 8.7 BHN Tested each day for 2 weeks.

325*F then dropped into cold water

Little change
8.2
8.2
8.2
8.2
9.0
8.7
9.5
9.2
10.4
9.8
9.2
10.4
8.7
10.1
9.8

-------------------------------------------------------------------------

350*F

10.4
14.3
15.4
15.4
16.6
15.4
16.0
17.9
16.6
17.2
15.4
16.0
17.2
17.9
16.6

-------------------------------------------------------------------------

375*F

12.5
15.4
14.3
15.4
15.4
17.2
15.4
16.6
17.2
15.4
16.6
16.0
14.3
14.3
13.4

------------------------------------------------------

400*F

19.3
17.9
17.9
20.9
23.8
20.9
31.4
22.7
17.9
19.3
20.9
22.7
21.8
19.3
20.9

[onondaga]

BulletFactory,

Looks normal to me up to 375. I've never gone higher than that. Check them next year for the next surprise....They go back down! now you know the alloy has antimony in it or it wouldn't have responded to the heat treatment so well.

Gary

[BulletFactory]

They go back down? How do you make bullets for long term shtf kind of storage? If I ever solve this leading issue, the first think I plan on doing is making a couple thousand rounds to put in several different locations.

[runfiverun]

they come down and stabilize. they'll hold that stabilization for 3,5,6 years maybe longer.
then they will lose hardness over time [long time]
but they won't get any softer than the alloy they origionally come from.
and can always be re-heat treated.
or if you want them hard,hard oxidize them, lead oxide is like 35 bhn. :lol:
brass hardens over time and loads can change because of this too.

[BulletFactory]

loaded rounds can be heat treated? Im not sure if thats a good idea.

[onondaga]

It is not so bad that they come back down. just plan for it. I cast bullets that stay hard by making an alloy that casts hard. I use Wheelweight:Lino at 7:3 and 7 day BHN is 14 and stays there. Straight Lino casts really hard too but is getting hard to get and price is going.....

Gary

[lwknight]

The easiest and slightly more expensive way to keep hardness status quo for a long shelf life is to mix it to the hardness without heat treating.
Heat treating is either for extreme hardness or for cheapskates that don't want to buy antimony.

If you wanted something like 15 bnh to remain constant , use the 2-6-92 or add a small amount of silver for even harder bullets.

When keeping the tin to 2% or so the age softening is minimal. I found some old 20:1 bullets that were soft as pure lead. I recast the same alloy and they were fairly hard. As far as I kinow , antimony will not soften with age but tin will.

Since antimony is the main hardener and the tin is minimal the tin softening will not offset the antimony hardening.

[BulletFactory]

Once I find a hardness/powder/lube combination, I really don't want anything changing. My goal is to make a round that works well, shoots well, and stores well. I'd like to just set up my dies, pick a powder and lube, and stick with that. I'll make a stockpile, and just shoot, reload, reshoot, and repeat the rest.

[kbstenberg]

Bullet Factory If you don't mind me adding to your question.
A good form of fairly cheap antimony would be hard shot for Shotguns? Then doing the Math to figure out to get to the 6% level for the Alloy?
Gary what % of WW/Line do you use for the harder original BHN? An most imp. to me what kind of expansion do you get out of that hard of a bullet?
I have other unanswered Questions but I don't want to comp. hijack the thread!
Kevin

[onesonek]

Bullet Factory If you don't mind me adding to your question.
A good form of fairly cheap antimony would be hard shot for Shotguns? Then doing the Math to figure out to get to the 6% level for the Alloy?
Gary what % of WW/Line do you use for the harder original BHN? An most imp. to me what kind of expansion do you get out of that hard of a bullet?
I have other unanswered Questions but I don't want to comp. hijack the thread!
Kevin

If I remember right, "hard shot" or magnum shot, is only about 4-5% Sb. That would make it tough to get to a 6% without adding something like lino or Roto's SuperHard. The shot by it's self would do for a number of applications with a bit of tin added however.
Expansion, depends heavily on speed, design, alloy, as well as bhn. Some design's don't require any expansion. Likely why larger diameter flatpoints work well without expansion. They rely on shape and momentum/penetration to do the work. Smaller caliber's are more critical in the balance of alloy, pressure, and speed as far as I understand. I don't know that there are any set rules,,I did read once and only from one source however, that if you run a 100 fps + per BHN you get some expansion, higher velocity more so. Under 100 fps you get little if any.

I haven't had time to test this in test medium as of yet, but intend to when the weather is more friendly.



Once I find a hardness/powder/lube combination, I really don't want anything changing. My goal is to make a round that works well, shoots well, and stores well. I'd like to just set up my dies, pick a powder and lube, and stick with that. I'll make a stockpile, and just shoot, reload, reshoot, and repeat the rest.

I know what your driving at or looking for,,,unfortunately, nothing is ever constant,,,even time itself is not constant. We do like to look for some degree of consistancy however. Being I don't have 20 yrs experience, I can only go by that of the experience of other's and to a point, already mentioned. From what I have read/heard so far, and from more than one source, age softening is slow, it likely won't affect much to any degree. More than age softening of say 1-2 points in time, would be if you had 3 + or - swings in bhn to start with. Hence is why heat treating aids in consistancy, over other hardening techniques. If they are consistant now, they will be consistant later,,,only different. Just remember, fit is king, everthing else is secondary.
Consistancy is relatively easy, perfection is nearly impossible, change is inevitable.

[bumpo628]

9.6 lbs of magnum shot + .4 lbs of 50/50 solder gives you:
2.0% Tin, 4.8% Antimony

[runfiverun]

loaded rounds can not be heat treated.

my 44 mags do fine with ww alloy, maybe thats why i keep a 7 gallon bucket full of 429421's,452664's for the 45 colt, another bucket full of 200 swc's for the acp, another one full of rnfp's for the 357.
a three gallon bucket full of 4/6 alloy boolits for the 308 the 223, 30-30's and 0-6.

moly coating them may change the game some, and paper patching would work too with plain alloy.
but you'd have to protect the paper with a wax of some sort.