Sorry if not posting this in the correct section...

I am helping a friend with a video-shoot, where we need to effectively "blow up" small blocks of plaster (say 6" x 6") while filming with high-speed video equipment.

To save from running out of test blocks, what would be the best caliber and bullet-type combo to essentially create the most explosive effect on these plaster blocks? My original thought was using a .243 with a high speed plastic-tip round. Or would something like a .410 or 12 gauge slug create more surface damage?

I have a variety of rifle or hand gun loads/calibers that we could use.

Any thoughts?

Thank you!!