Alloy difference

[Frank]

Mix A casts at 775'F, cools the sprue in 6 seconds and water drops to BH 27.

Mix B casts at 670'F, cools the sprue in 13 seconds and water drops to BH 27.

What is the difference?

[Defcon-One]

The difference is 105 degrees and 7 seconds!

Ok, Ok. Somebody was gonna say it. Sorry!


(I assume that you are using the same thermometer, pot, mold, etc.)

My guess is Tin content. But that is just a guess.

I am curious and can't wait to hear what the pros say!


Update: Now it sounds like he had all Pb, Sb in mix "B" with no Tin at all. He kept adding Antimony again and again..... Mix "A" probably had more Tin.... he was trying to reproduce that with only additional Antimony, no Tin, which created the big difference. I still say so, but nobody here even mentions Tin at all?

The lesson is, know what you have, know where you are going and have a plan on how to get there. If you just throw "stuff" in the pot, you wind up with this question!

[BABore]

Both are the same or similar alloy. Mold temperature is the difference and likely the mold size or material

[Frank]

BABore:
Both are the same or similar alloy. Mold temperature is the difference and likely the mold size or material
Both are Lee molds. I'm water dropping also. Mold B needed to be harder, and the pot was running low, so I put whole bar of pure in the pot, and added antimony. I cast a few, did a BH test. Not hard enough, so I added more antimony. Casted a few again, tested. Not hard enough, so I added more antimony and some magnum lead shot. Now my melt was not solidifying. So I had to cut back on the heat. I was at 750, now I'm down to 670'F and the sprue still won't solidify. So I use my fan to speed the cooling up, cast 50 or so like these and call it a day.

So I've got two boolits that have the same hardness readings. There must be something different about these alloys.

[44man]

The difference is I can list all of the alloys that can measure the same BHN----OOPS, I can't! :bigsmyl2:
It is like wood shafts. Gather 10,000 shafts from the same wood, all the same diameter and measure the stiffness to expect them all to be the same.

[Frank]

44man:
The difference is I can list all of the alloys that can measure the same BHN----OOPS, I can't! :bigsmyl2:
It is like wood shafts. Gather 10,000 shafts from the same wood, all the same diameter and measure the stiffness to expect them all to be the same.

In other words, I was using up the last of what I had, store bought bullets that didn't shoot, last WW muffin, for Mix A, then the last bar of lead, added antimony and mag shot for Mix B. So when I ran out of Mix A, I used trial and error to get the same BH out of Mix B and I got it. But maybe the alloys are different really, like the wood shafts. I'll have to make a note what is in each and see how both respond with the standard load.

[fredj338]

My vote is the added antimony.

[onondaga]

I suggest that you buy big consistent lots of alloy for consistent results. I never buy less than 100 pounds of WW in a consistent lot. I buy Linotype in 50 pound lots.

For my basic hunting alloy I mix 7#ww with 3# Lino = BHN 14 air cooled

Frank, straight Lino will be close to what you are getting.

Gary

[Frank]

Onondaga:
suggest that you buy big consistent lots of alloy for consistent results. I never buy less than 100 pounds of WW in a consistent lot. I buy Linotype in 50 pound lots.

For my basic hunting alloy I mix 7#ww with 3# Lino = BHN 14 air cooled

Frank, straight Lino will be close to what you are getting.

Gary
Great idea. I don't want it too brittle though. I could mix it with pure and get what I need.

[onondaga]

Straight Lino definitely is so brittle that it shatters on impact. In general, alloys harder than 18 BHN shatter on impact. I use straight Lino in .223 Rem loads at times, at hi velocities 2550 fps and up. They definitely shatter.

Tell me what caliber, bullet design and purpose for the ammo, then myself and many others will have suggestions. I really don't know what you are looking to accomplish. But bullet hardness isn't all that important with gas checked bullets that fit properly. Fit is the hard part, really. The rest is easy.

Gary

[Frank]

Onondaga:
But bullet hardness isn't all that important with gas checked bullets that fit properly. Fit is the hard part, really. The rest is easy.

A consistent recipe for big bore handguns, like my BFR's, is what I'm looking for. A very hard boolit of 27 usually works best in the 45-70 revolver, but they are water dropped, so for me it's really water dropped WW's with added antimony that works the best. But the WW's vary in composition, so getting there sometimes can be a problem. But using consistent metals in fixed proportions would solve the problem. For hunting, a hard big bore boolit doesn't need expansion, unless it is driven too fast. Hollowpoint is a cure for speed, but it destroys meat. Sometimes a boolit design shoots well if it is a softer, but it must have GC, and there are no guarantees. Plain base boolits always need to be very hard for the revolver.

[fredj338]

Onondaga:
For hunting, a hard big bore boolit doesn't need expansion, unless it is driven too fast. Hollowpoint is a cure for speed, but it destroys meat. Sometimes a boolit design shoots well if it is a softer, but it must have GC, and there are no guarantees. Plain base boolits always need to be very hard for the revolver.

Not always. I shoot a 45/270gr cup point, 25-1 alloy, expands nicely & stays together well @ 1000fps. A good bullet for hunting just about anything in NA. Same for my 44/270gr cup point @ 1200fps, but it does run w/ a gc, it's the way the mold came. Cast them 20-1 or 50/50 ww/lead they still shoot well but expand a bit less. Straight ww, little to no expansion, maybe a bit of point deformation. What I would use for large heavy game like elk or moose or for def against big bears.

[Frank]

fredj338:
Not always. I shoot a 45/270gr cup point, 25-1 alloy, expands nicely & stays together well @ 1000fps. A good bullet for hunting just about anything in NA. Same for my 44/270gr cup point @ 1200fps, but it does run w/ a gc, it's the way the mold came. Cast them 20-1 or 50/50 ww/lead they still shoot well but expand a bit less. Straight ww, little to no expansion, maybe a bit of point deformation. What I would use for large heavy game like elk or moose or for def against big bears.
With soft you lose accuracy in the revolver. Sure, a soft boolit can take game, but how well does it shoot?