Mike--Problems with the .35 Whelen. Add some tin that will fix it. Try it and report back.
Alloy for bullet casting can't be tempered. Your hardness reading will vary depending how long it has set after melting. Hardness testers only measure the surface and how deep the hardness goes is not known. If you were making knives for example, knowing the hardness could be very useful. To me, for bullet casting, it would somewhat be like knowing the voltage going to your spark plugs.

The Whelen bullets are caste with Lyman #2 alloy from Rotometals exclusively. I don't think adding tin will be the fix.

I believe I know what the problem is with the Whelen... using IMR 3031 for the loads, and it just doesn't seem to like that powder. I will try IMR 4064 and start working them up with that.

That was the change I made for the Garand, also, and 4064 worked beautifully. I went from getting a very fine layer of leading, to none. Provided I can duplicate these results at the range again, I will be done with load development for the Garand, as the accuracy was better than my jacketed bullets. Function was flawless.

I hope the Whelen responds the same way.

Mike. I was being facetious again, I pretty well knew adding tin is not going to fix the problem.

Mike, if you got Lyman #2, it already has 5% tin in it. (It is 90/5/5...) There is no reason to use that much high-priced tin in projectile alloy, and the LAST darned thing you need is more tin! In my estimation, pure lino shoots extremely well in rifles, and anything over about 2% in handguns is a waste. (But I might have said that before...)

Even lino is only 4% tin, if memory serves, and it casts absolutely gorgeous projectiles. I may be wrong, but I believe lino is 84/12/4, and the 12" is antimony.

Doubless, I have some tin, but it is being saved for another project... LOL!!! It's certainly not going into Lyman #2.

I tried Lino in the Garand, and she shoots it pretty well, with just a slight haze of leading at the end of the barrel.

The #2 has actually reduced the minimal leading I was getting with Lino. Using the IMR 4064 reduced the leading to non-existent, and shot a really nice 4 shot group, with the 5th shot as a flyer, at 100 yds.

Mike, I like 4064. When I started loading, I started with a 30-06 and used 4064. I use 4064 in others. For years I kept hearing 4350 is THE powder for the 30-06. I tried it and 4064 works much better in my rifle.