I went ahead and cast up a dozen out of the harder alloy. It appears that the new harder bullets are .002 to .003 inches smaller than the ones cast out the pure lead. However, in measuring these I found that the mold doesn't throw perfectly round bullets, measured one way ,(across the parting lines), the seem to be 3 to 4 thousandths larger than when measured at 90 degrees to the lines. This means that the out of roundness is more than the difference between the hard and soft lead bullets.
I am hoping that the small reduction in size will help the bullet/wad combination to enter and go through the forcing cone area without creating quite as much pressure. If the soft lead slug noses have been swedging down any as they go through the forcing cones, then this may be a mistake, I just don't know.
Daryl, You are correct about the wads being the ones they recommend, but as far as I can tell, they have been discontinued and the replacement wads are now Clay Busters. I did measure the thickness of the wad petals and the Clay Busters are 1 to 2 thou. over the AA wad thickness. The hull thickness at the mouths of the Federal cases and the old AA cases seem to be about the same thickness.
Iowa_303, I had added part of a bar of Tin to my 10 pound lead pot but didn't have any Antimony so I dumped in a large handful of old reclaimed shot. It should have at least some Antimony in it, probably Arsenic as well! That's another reason to always do your bullet casting outside! It was chilly outside yesterday and windy too. I had to put up a piece of plywood to block the breeze and I still had to run several bullets and remelt them because of wrinkles caused by the mold not being hot enough.
I intend to try these out today and will report back to you guys on how they worked out. It seems like these chambers must be a little too tight but I have taken them down to full depth according to my chamber gauge and even went in with the long forcing cone reamer and relieved a bit more of the lead in the chambers. These are really light weight barrels and I can't afford to take any more metal out of the front of the chambers in them. I hope to find the right answer today. Bob