Am I wasting tin?

[DtheD]

I cast for my '88 Trap Door 45-70 using a 20:1 ratio of lead & tin. I've read this was the original ratio. But, if anything over 2% is wasted why did the government war dept. in it's infinate wisdom, use this ratio? Should I cut back? I use a 50-50 roll of solder and 9 1/2 lbs of pure lead. I feel I'm using way too much tin. Any ideas?

[cajun shooter]

Look for the LASC post on bullet alloys. They have over 10 pages of info on your question. Also read all the post of Glen Fryxell. Then buy the Lyman Cast bullet Book. I think after you read all this you will have a better understanding of alloys and the part they play. I printed out the info that I referred you to and put it in a binder in my shop where I cast. Even after 30 years I will refer back to these writings. The LASC stands for Los Angeles Silhouette Club

[BABore]

The tin used in your 20 to 1 alloy is being used as a hardening agent. It also allows for better fillout over pure lead. There is nothing wrong with your tin usage in this type of alloy.

What most are referring to as a waste of tin is when combined with a antimonial type alloy. Most commonly WW's. Some have trouble with fillout unless a bit of tin is added. 1/2 to 1% is typically all that is needed. Any more is being wastefull. I try not to use any tin additions unless the mold configuration absolutely demands it. Most fillout problems are from things other than alloy.

[44man]

The tin used in your 20 to 1 alloy is being used as a hardening agent. It also allows for better fillout over pure lead. There is nothing wrong with your tin usage in this type of alloy.

What most are referring to as a waste of tin is when combined with a antimonial type alloy. Most commonly WW's. Some have trouble with fillout unless a bit of tin is added. 1/2 to 1% is typically all that is needed. Any more is being wastefull. I try not to use any tin additions unless the mold configuration absolutely demands it. Most fillout problems are from things other than alloy.
Plain and simple, right to the point and correct! :drinks:

[BABore]

Thanks Dad! :bigsmyl2:

[BABore]

I cast for my '88 Trap Door 45-70 using a 20:1 ratio of lead & tin. I've read this was the original ratio. But, if anything over 2% is wasted why did the government war dept. in it's infinate wisdom, use this ratio? Should I cut back? I use a 50-50 roll of solder and 9 1/2 lbs of pure lead. I feel I'm using way too much tin. Any ideas?


I forgot to mention my ideas. Use half WW's and half Pb. Drop them air cooled from the mold. They should run 9-10 bhn which is real close to what your 20 to 1 mix is. If you need real hard boolits, water drop them for around 18-22 bhn. Otherwise, increase or decrease the Pb content to get the boolits where you want them. A WD'd alloy of 35/65 WW-Pb will run around 15-16 Bhn to give you an idea. I've rarely found the need to add tin to any of these alloys.

[44man]

I forgot to mention my ideas. Use half WW's and half Pb. Drop them air cooled from the mold. They should run 9-10 bhn which is real close to what your 20 to 1 mix is. If you need real hard boolits, water drop them for around 18-22 bhn. Otherwise, increase or decrease the Pb content to get the boolits where you want them. A WD'd alloy of 35/65 WW-Pb will run around 15-16 Bhn to give you an idea. I've rarely found the need to add tin to any of these alloys.
I have a question for you. I need a boolit that will expand a little for my 45-70 BFR for next season yet still need a hard drive area. The boolits are too fast at 1650 fps and internal damage on deer is poor. I was going to cast with pure noses and my hard alloy for the drive.
Do you think 50-50 will give some nose expansion?
The only way for me to find out is to shoot a deer. I know water dropped 50-50 shoots very well out of the gun.
Deer are not very large and fast boolits just zip through even with a WFN. I hate deer going 3 or 4 times farther and finding intact lungs, compared to the .44, .45 and .475 with hard cast that just destroys the insides.
I never thought a higher velocity would take away the effect of WFN boolits until I started using this revolver.

[BABore]

You will get some nice expansion at 1,650, with a WD'd 50/50 alloy. You don't have to shoot a deer either. You have a know deer boolit, right? Shoot it into well saturated newspaper and see what it does. Then shoot a 50/50 alloy boolit and compare. Same as solving an equation. Now if'in you want real performance, cast and WD some 50/50 boolits. Size and GC or whatever you normally do. Before lubing stand them up in a pan of water filled to the top driving band. Heat the noses with a propane torch til you get a slight color change. Similar but opposite of when a fresh poured sprue cools. Let them set til cool and lube them. You'll end up with a 10 bhn nose and 22 bhn bearing. Note: the annealed portion will be almost pure lead soft for about 12-24 hrs then it will go to 10 bhn and stay. A 400 F Tempil stick (welding supply) is a much more precise method of heat control.

[44man]

OK, I will give it a try. By next season I will have a selection to try on actual animals too. We will do some more testing this summer on wet paper.
Right now I can't keep enough papers in the garage. We kept two puppies from my hussy dog. :mrgreen: Might as well leave a garden hose run in their pen. Can't leave them outside in the cold.

[BABore]

OK, I will give it a try. By next season I will have a selection to try on actual animals too. We will do some more testing this summer on wet paper.
Right now I can't keep enough papers in the garage. We kept two puppies from my hussy dog. :mrgreen: Might as well leave a garden hose run in their pen. Can't leave them outside in the cold.


Well, as long as the newspapers are well saturated. :takinWiz: Your the one that has to pick through them.[smilie=1::-D