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lead chucker
02-20-2012, 12:29 AM
I have been using 4% tin in my 50/50 mix WW, lead I want my hollow points to fill out completely. Do you think that's too much. Tin is expensive and I don't want to be wasting it if 2% would be adequate. Any HP casters out there that can give me some advice.

runfiverun
02-20-2012, 02:04 AM
yes that is waaay too much.
i never add more that 1% tin to 50-50.
the less antimony you use in the hollow point boolits,the better they will hold together when they open.
if you are using a gas check 30-1 alloy opens real easy and stays together at handgun velocities.
if you are using them in a rifle i'd stick to the 50-50 and 1% tin and water drop.
this will allow you to push them in the 1900 fps range and still get the benefit from tthe hollowpoint.

get your h/p pin hot and keep it hot throughout the casting session.
keep a fast pace while casting to keep the mold up to temp. 3 pours a minute isn't too fast and 4 should be about right with a 700* alloy.
remember mold temp and pace is more important than alloy temp.
you can always throw them back into the pot untill you get the rythmn just right.
do a quick run of 50 then look at them, then adjust.

geargnasher
02-20-2012, 02:11 AM
+1 R5R, I've fussed with HP casting quite a bit and would describe my methods exactly the same way. And no, I haven't been peeking in your reloading room window! :grin:

Lead Chucker, print that out and post it on your gun room wall, you'll be happy with with the results both with the casting and with the shooting.

Gear

lead chucker
02-20-2012, 02:47 AM
Runfiverun

That's the kind of answer I was looking for thank you very much. I was wondering if water quenched 50/50 + tin would be to hard. I'm shooting for over 1800 fps in my 308 with the 311299 it has one cavity with a hp I have cast up some 3 parts lead to 2 parts WW + tin quenched in snow slush water. Thinking it would be soft enough to expand but still stay together. I have not had the chance to shoot them yet. Thanks again.

44man
02-20-2012, 09:26 AM
Just what affect tin has with pure lead, I don't know but it does not add much hardness. I feel it adds some toughness by helping lead molecules to stick together.
That is the only reason for use with an antimony alloy and using too much is a waste of tin. Anything over what is needed for atoms to bind is too much.
Using more sure doesn't hurt anything but your pockets.

cbrick
02-20-2012, 09:41 AM
For the metallurgy of it you don't want the Sn percentage higher than the Sb percentage. For the 50/50 your using that would be about 1% Sn. 4% is a huge waste of tin and will gain you nothing except having 4 times less tin than you had.

You didn't say what your shooting so I'll assume your talking handguns so NO, don't water drop them. It will be detrimental to mushrooming at handgun velocities and probably not needed at typical rifle velocities either. My 308 shoots air cooled clip-on WW +2% Sn (about 11-12 BHN) at 1900 fps very accurately with zero leading, both HP and FP.

For HP fillout (or any other bullet) the trick is a properly heated mold AND spud. A cool HP spud will never give well filled out HP's.

Rick

Larry Gibson
02-20-2012, 11:43 AM
I've been using 2% tin with WWs for some time. I then, when making 50/50 with lead, add 50% lead to the already made WW=2% tin. Both make a very good alloy and fill out completely in the mould.

Larry Gibson

44man
02-20-2012, 01:08 PM
I just checked BHN on a stick of pure tin for fun.
Now we all know tin is hard and a stick creaks when you bend it.
But when trying to reach the set point, the pin kept going in and after about 10 readings on both sides of the stick, I kept getting 5 to 6 BHN! Mostly 5. :???:
I don't know what it is doing, the metal is either moving away from the pin or compressing so it shows how useless a BHN reading can be.

44man
02-20-2012, 01:49 PM
OK, I just went and found a thick stick of 50-50 to fit the tester, half pure lead and half tin, now that is 50% tin.
I get a BHN of 9 to 10 on the high side so if anyone thinks they can harden pure with tin and keep making it harder by adding more and more---SURPRISE! [smilie=1:
So the question comes to mind, is a 30 to 1, 20 to 1 or 16 to 1 any different? Once a certain amount of tin is added, does more do anything at all as far as shooting the stuff?
Elmer liked 16 to 1 and called it hard.
The closest I have is a 20 to 1 boolit and it measures 6 BHN.
What I have here is that lead and tin will age soften very fast and any hardness that tin adds will be gone in a month or so, means you need to shoot them up FAST.
Adding too much tin to an antimony alloy will also cause the boolits to age soften much faster then a proper alloy.
But does age softening according to BHN change the way the boolit will shoot? I kind of doubt it!
Just too much is made of BHN and since the pressure limits you read about are based on BHN that will change in your alloy with time, you are just wasting your time.
Maybe Lee, etc should have put a time limit with those pressure figures so you need to shoot them within 9.72345 days or the pressure has to change.
This is fun guys! :kidding::bigsmyl2::bigsmyl2:

geargnasher
02-20-2012, 02:22 PM
44Man, I've been through the same tribulations trying to determine the BHN of pure tin. You want some more entertainment, try looking it up on the internet and gettin two sources to agree!

I think the issue is that the 5/32" ball pressure test is the wrong range of BHN test to accurately measure tin. Once you start alloying tin and pure lead, it becomes measurable and predictable.

Gear

Gear

44man
02-20-2012, 03:00 PM
I guess it is why us old timers ignore all the books, rags, etc and just worry about min and max load info. [smilie=w:

lead chucker
02-20-2012, 03:53 PM
Cbrick
I mentioned it's a 308 and I wanted to be able to shoot 1800 fps or better, bullet is 311299 hp. So now I know 4% tin is too much and 1% should do it. Water quenching should make it hard enough and still be malleable enough to have the hp expand.

Larry Gibson
02-20-2012, 04:48 PM
Cbrick
I mentioned it's a 308 and I wanted to be able to shoot 1800 fps or better, bullet is 311299 hp. So now I know 4% tin is too much and 1% should do it. Water quenching should make it hard enough and still be malleable enough to have the hp expand.

I push that bullet HP's and 311041 along with others to 2200+ fps for hunting with the WW + 2% tin + 50% lead alloy as mentioned. It workes very very well.

Here is the 311299s kissin' cousin, 314299, cast soft and HP'd with a Forster 1/8" HP tool loaded in the 7.62x54R.

Larry Gibson

USSR
02-20-2012, 07:56 PM
I have been using 4% tin in my 50/50 mix WW, lead I want my hollow points to fill out completely. Do you think that's too much. Tin is expensive and I don't want to be wasting it if 2% would be adequate. Any HP casters out there that can give me some advice.

lead chucker,

No, 4% tin is not too much with a 50/50 mix that is to be used for HP's that you want to drive at 1800fps. I do it all the time, but I would suggest you either water drop or heat treat them.

Don

cbrick
02-20-2012, 08:29 PM
Cbrick, I mentioned it's a 308

Oh yeah, in post #4. I was going by post #1, sorry bout that.

Rick

fredj338
02-20-2012, 09:09 PM
I get great results w/ 25-1 lead/tin. So 1% in your 50/50 would be more than enough for fill-out.