Alloy Blend Sanity Check

[Dimner]

Okay, quick sanity check before I blend a bunch of small batches of alloy that I have procured over the years. My goal is to make a multi-use alloy that I can use without alteration for 90% of my casting. Then have some ingredients on hand as 'pot sweeteners' if I need to make a pot full of an alloy for special needs.

I have plenty of linotype, 99.5% pure tin, and pewter on hand, so I'm not really concerned about wasting tin. If it helps the alloy, it helps me.

95% of my casting is for Rifle and I powder coat everything I can. The only time I do not powder coat is when the PC works against me. Most casting is for 30cal with some PC/heat treated 22cal thrown in. Unless I'm working on a special project, for the 30 cals, I do not go over 2100. For the 22, it's for an AR15 pushed to 2400fps.

So gut check time:
multi-use alloy: 96pb/2.5sb/1.5sn - would it be any benefit to goto 95/2.5/2.5?

I'll keep on hand about 300lbs of blended CWW that I'm getting tested.
As well as 450 lbs of indoor range scrap that will be tested.

To get my multi-use alloy, I will start with my range lead and blend in various 50-75lb batches of alloys that I have been sitting on unused. Lyman #2, some 'HardCast' Alloy (95.2/4.7/0.1), and SWW. Then using my alloy calculator adding tin, pewter, and linotype until I reach my desired composition.


So, with all that said...... What part of my plan makes you cringe? Makes you say: "oh god, don't do THAT!" What am I missing and what should be changed?

 

[JonB]

The alloy I prefer to use for Rifle and Mag Pistol is 94-3-3
If it was the only alloy I had, then I could cut it with 50% pure lead for 97-1.5-1.5 for low pressure loads.

It's been written, that a alloy with balanced Tin and Antimony is the "toughest" and will better hold together when it hits a target.
That's my 2¢

 

[RicinYakima]

All I have is an opinion, as never shoot cast that fast. In theory if the tin and antimony are in equal parts of less than 5% each, there will be not crystals of antimony in the alloy to make it brittle. Either of your multi-use alloys would be just fine the speeds I shoot, less than 1750 f/s.

 

[Ian]

So gut check time:
multi-use alloy: 96pb/2.5sb/1.5sn - would it be any benefit to goto 95/2.5/2.5?

YES, Ric explained why. Also consider the side effect of a few ten-thousandths more bullet diameter and a grain or three less bullet mass, but both are minimal and unless you have custom moulds you're going to be sizing the bullet down a lot anyway. Any more than 2.5/2.5 is not necessary up to and probably beyond the pressure and velocity absolute limits of the cartridges you mentioned....IF you powder coat and use gas checks.

Reserve richer alloy (somewhere around 5/5 with never more tin than antimony by mass [not my moles]) for greased high-velocity rifle bullets, or just heat treat the 2.5/2.5 up to 18 or 20 bhn.

 

[Dimner]

After starting to powder coat, I really don't have any interest in lubing bullets other than some of that beautiful BLL for my loads 1250fps and below.

If I hear you all correctly, there really is no reason to do a 2.5/1.5 alloy. Better to just make it 2.5/2.5 and be done with it. Will a 2.5/2.5 alloy cause me any issues or snags at 1250fps and below? (Either with BLL or PC)

The 2.5/2.5 sounds pretty good either way and ad JB said, i can always "de-sweeten" a pot with some pure or SWW. But if it works for the low velocity stuff all the better.

 

[popper]

You can H.T. the 2 1/2% alloy but I tend to go toward 4% for HV 308. With a 1:10 twist it needs tougher so I use 0.5% Cu and no tin. Just loaded a bunch of 308 165gr GC over 40gr I4895, haven't shot the beast in a while.
Talk about hard alloy - neck not flared enough. Bullet is in decent shape, GC is crooked now.

 

[RicinYakima]

If I hear you all correctly, there really is no reason to do a 2.5/1.5 alloy. Better to just make it 2.5/2.5 and be done with it. Will a 2.5/2.5 alloy cause me any issues or snags at 1250fps and below? (Either with BLL or PC)

When linotype was cheap and easily available, I shot it in 38 WC loads and 45/70 loads. As long as it fits, it will shoot.

 

[Bret4207]

Fit is more important than specific alloy, but I'd go with the 2.5/2.5. If nothing else, it makes things simpler.

 

[Dimner]

Revisiting this for a moment.

How well will a 2.5/2.5 alloy going to perform on deer in the 2000-2100fps range?

I have been churning through all kinds of threads on hunting alloys and I am struggling to find an alloy that doesn't include clip on wheel weights in some proportion. Fiver had a great point mentioned it in a different thread

here is something to think about so you can be completely confused.
50-50 what?
right..
ww's and soft lead.
well there's ww's with 4% antimony from you know back in the 70's and 80's up till the 90's even.
then there is what I'd call 'modern' ww's, their alloy is more like 2.5-3.0 % antimony.
cutting the first ones in half gives you just under what the second ones start out as.
not much difference between a 3% and a 4% alloy cut in half until you go throwing 2% tin in the mix then you have a balanced alloy or a tipped over too much tin alloy.

So, alloy composition wise, PB/SB/SN, what will work hunting wise if the 2.5/2.5 isn't going to expand?

 

[popper]

multi-use alloy: 96pb/2.5sb/1.5sn - would it be any benefit to go to 95/2.5/2.5?
Why bother with the tin? I don't use any, not a problem. Cu is cheaper and does almost the same job as tin. Prevents Sb from globing and brittle. Excess tin tends to glob also but 50/50 tin expands real well.
If I were to do what you are doing, I'd smelt batches of all (scrap and known), then cross smelt to get all the same. You have a constant base to add 'spices'. And you only have to pay to get that batch tested.
Hard alloy doesn't hurt anything, soft may expand, depending on the mold and fps. This is 40sw TC into a rock pile. ~950 fps. Ended up pretty much cylindrical. No real weight loss. 4% + a tad of Cu. Yup, they were coated. No, not a 'pretty' mushroom but went tail to snout of a hog. 30/30 185gr GCd 1% Sn/Zn/Sb only expanded to 45 cal out of a hog gut. Didn't penetrate the shoulder. An experiment I don't use anymore. I want 2 holes!

 

[fiver]

2.5/2.5 will expand but in a different way/time.
the higher speed will help some, but the meplat is going to be the deciding factor on what happens.
anything that happens to the nose before the round is fired will make a difference when it gets there.
flat point, cup point, wide hollow, short thin long deep thin etc..
they will all influence the penetration, what happens to the front of the bullet,,, and maybe even cause the bullet to tip after punching through the skin.

it's like a jacketed bullet with a 1% antimony core and a 3% antimony core.
the core has already had the antimony broken down, unless it's poured in, or melted to bond it to the jacket.
so your then getting a different reaction from all of those variations.

does it matter?
your talking about 2-3 inches of when what happens, and whether you get a shred of shards or a punch through with a nice mushroom.

now Tin.
see Tin modifies the internal chain and bonds with both the antimony and the lead.
thus strengthening the bullet against any shear forces.
that's why the some higher velocity is needed to mimic a lower tin alloy at a slightly lower speed.

trying to not split hairs with the alloy here, if you exceed their 'ability' your not gonna have a deer bullet so much as a varmint bullet.
just wanting to point out that the meplat and the velocity are tied together more than the alloys ability to overcome either one.
it's more along for the ride and only makes a difference in the shear strength or ability to stay together [malleability] when it gets there.

 

[Dimner]

2.5/2.5 will expand but in a different way/time.
the higher speed will help some, but the meplat is going to be the deciding factor on what happens.
anything that happens to the nose before the round is fired will make a difference when it gets there.
flat point, cup point, wide hollow, short thin long deep thin etc..
they will all influence the penetration, what happens to the front of the bullet,,, and maybe even cause the bullet to tip after punching through the skin.

it's like a jacketed bullet with a 1% antimony core and a 3% antimony core.
the core has already had the antimony broken down, unless it's poured in, or melted to bond it to the jacket.
so your then getting a different reaction from all of those variations.

does it matter?
your talking about 2-3 inches of when what happens, and whether you get a shred of shards or a punch through with a nice mushroom.

now Tin.
see Tin modifies the internal chain and bonds with both the antimony and the lead.
thus strengthening the bullet against any shear forces.
that's why the some higher velocity is needed to mimic a lower tin alloy at a slightly lower speed.

trying to not split hairs with the alloy here, if you exceed their 'ability' your not gonna have a deer bullet so much as a varmint bullet.
just wanting to point out that the meplat and the velocity are tied together more than the alloys ability to overcome either one.
it's more along for the ride and only makes a difference in the shear strength or ability to stay together [malleability] when it gets there.

Okay, I think I'm following you. Let me summarize in my own words so I can see if I am understanding this correctly. I'm that guy who should wear a hat that says lost in translation.

Meplat ..... Velocity ..... Alloy

They need to be in balance to get the desired:

Penetration ..... Expansion ..... Malleability(maybe this goes with expansion since the opposite of Malleability is a varmint bullet type shatter)

With a 2.5/2.5 alloy, the Sn/Sb bond will strengthen the bullet and allow us to avoid the varmint bullet explosion, but only up to a point. That threshold is determined by velocity and meplat. Change either velocity or meplat and the bullet performance changes.

Hopefully I summarized correctly.

Now to put that in practical terms....

1800fps + My bullet + 2.5/2.5 = probably not much expansion, but I'm guessing decent penetration.

2050fps + My bullet + 2.5/2.5 = Will likely perform how I want it. Mushroom with ample penetration.

2200fps + My bullet + 2.5/2.5 = Likely exceed the malleability of my bullet upon impact or first 2/3 inches. Not good for penetration or meat on the table.

Bullet design I'm using is the one I have been playing around with in other threads. Large Meplat 0.225"



I should also caveat that I am not dead set on 2.5/2.5 for a hunting bullet. This thread began when I was deciding on what general alloy I wanted to keep on hand in bulk. I have 200lbs of 2.5/2.5 currently. I also have the supplies on hand to alter that alloy on a pot by pot basis for specific uses. I have no problem altering 20lbs of this alloy if there is something that is more practical.

 

[fiver]

i think you got it.
we are really talking about impact velocity when we talk about muzzle velocity.
or just like the big boys use,,, an impact window where the bullet performs just like the advertisement pictures.
it works the same way for jacketed and cast, only in different speed spectrum's.

your not likely to get a real nice picture perfect mushroom with a cast bullet unless you modify things [soft nose/cup point etc.]
the key to cast is straight line penetration and pushing stuff out of the way as it goes through.
the malleability is,,shrug,,well gonna help on the terminal perspective, but it kills your internal start.
the balance is the key, enough, enough, not too much... is pretty close to perfect.

 

[Bret4207]

What Fiver said- you aren't likely to get a mushrooming that looks like you get shooting into sand or wet paper. Flesh is different and the speed the bullet arrives on target or whether you hit bone right off will make all the difference. You have a FP, you have adequate velocity, the rest is shot placement.