A few split-tip casting questions

[John in WI]

I am planning on doing some more casting tomorrow. I have made some of dead soft lead, using paper in the tip of the mold. Someone suggested using aluminum foil instead so I tried it with an alloy 1:1 WW:lead with a bit of solder in in.

The problem I'm having is that aligning the aluminum foil is tricky, and by the time I get it right, the mold must be cooling off. So in the last batch probably 3 out of 5 had a wrinkle in the tip.

I tried speeding up the casting, but that pretty much resulted in getting burned. I tried heating up the alloy further, but that's not helping against a cold mold. So I'm wondering if I can try to align the aluminum foil in the mold, then re-heat the mold by setting it with a corner in the melt for maybe a minute? The casting would take forever at that rate, but if it would bring down the failure rate I would do it!

The other question I have is, now I have probably 20 boolits with a bit of aluminum foil in the tip. Aluminum melts quite a bit above lead, so I'm wondering if I can just re-melt them and skim off the aluminum? I really don't want to contaminate the whole pot (it's a small Lee "drip-o-matic"), but I'm also not sure if that tiny of a quantity would make much of a difference.

I'm hoping this slightly harder alloy will resist having the boolits literally torn in half on impact against phone books. Trying to dial in the perfect hardness vs. speed. (It might be a solution in search of a problem :guntootsmiley: )

[abqcaster]

You can skim it. Aluminum melts at twice the temp as lead and is much lighter. So it ought to float right to the top. good luck!

[runfiverun]

you are using the vent lines to line up the foil right?
i would just cast 4-5 pours and put them back into the pot then add the foil to one and pour ,then cast 3-4 more real quick till a pace/amount is found and a rythm is achieved.

[John in WI]

I gave it another try and seemed to have better success this time around. I actually bought a thermometer so I can stop guessing at the alloy temperature in my casting pot.

Then I got a dental pick so I can quickly line up the foil without burning the heck out of my fingers.

I cut the foil so that it is wide enough to go from the alignment pins to just about the shoulder (in front of the crimp groove) so it's more or less self-aligning The problem is sometimes when you close the mold, air currents make the foil want to blow out of the way.

Anyway, keeping the alloy a little bit hotter, and working a little bit faster has helped. But I think the big issue was that I wasn't paying attention to exactly HOW the lead was going in to the mold. Normally I didn't pay it much attention. But you could see on all the defects that one side was well formed, and the other was wrinkled. To me this says that one side is hardened or nearly hardenend before the other half of the tip gets a chance to fill up. So I was trying to line the mold up (level with the floor) and drop the lead straight down. In theory they should fill up at the same rate, and meet above the foil at the same temperature.

The success rate isn't great, but I don't need millions of them. I would just like to do more rigorous testing on the idea. Do they shoot as well as non-split boolits? (they should--IF they are perfectly symettric and no wrinkles--the aerodynamics and mass should be nearly identical). And also, try to dial in the right alloy for expansion without fragmentation at around 900FPS.

I'll try what you suggested--alternating split and unsplit boolits, just to crank up production a little faster and keep things hotter.

[Longwood]

Have you tried aluminum tape?

[Norbrat]

Try the trick used to cast soft nose boolits; before you open the mold, dip the corner of the mold back into the alloy until the sprue re-melts, then let it set and open the mold.

This should allow the alloy in the cavity to re-melt and hopefully fill any voids.

[Longwood]

Think of it this way,,, do you think those phone books care what you shoot them with?:kidding:
I have known lots of people that experimented with special Dum-Dum type bullets
Not one of them has ever used one for what it was intended.