HuntAway

I am wondering if you were not trying to load MMP HPH-12 sabots that normally come with a Hornady bullet.

I would not go to the "crush rib" unless you need to as I think it will be to thin for the Renegade and you will loose pressure, and before the "crush ribs i would suggest the MMP HPH-3p-EZ load. It is slightly thicker than the "crush rib". It also has shorter petals than the "crush rib"

In my Renegades I shoot either the 250 grain or 300 grain Gold Dot and I use an MMP HPH-24 sabot. The 24 sabot goes down very well and will provide a complete seal. The other alternative, especially shooting those short 240's is the Harvester regular sabot.

I know of know good way to tell which black sabots you have - whether they are 12's or 24's but from your loading description I would imagine 12's.