This may be a bit off subject but it is a current concern of mine so I am asking all the experts out there. I have a Lyman 12 gauge mold for the "sabot slugs" and have been using Winchester once fired hulls and AA 12 gauge wads to load these in and then they are star crimped. I have gotten good accuracy and good speed out of them so far doing this without any problems.
Winchester has quit selling the 12 gauge AA wads some time back so I was looking for a replacement load that would get me about the same speed using another wad. I called Ballistic Products to see what they would recommend and the tech told me that Clay Buster wads were the standard replacements for the AA wads. I also found out that they had new Federal clear primed cases on sale some I bought some of those as well. I was assured that they would be a good replacement for the AA hulls.
I loaded up a few of these using the Lyman soft cast slugs and fired a few of them in the rifled slug gun I am just finishing up. The hulls were trying to stick in the chambers and I know that the load is a recommended load by Lyman with only 9300 PSI., so I figured that the problem was that either the hulls were thicker or it might be that the wads were thicker. I measured the soft lead slugs at .685" across the from rim of the slug where it is largest.
Finally, here is my question, if I cast these out of harder lead will they be enough smaller to just relieve a bit of the pinching when they they leave the case mouth? I have some alloy that I hardened up by putting quite a bit of tin into it, it can just barely be scratched with a thumbnail.
Is there any way to know or predict how much the diameter will be reduced by using harder lead. Also, does the casting temp. of the metal make any difference in diameter size as long as the mold blocks are hot? Bob