I thought this was a very good site to compare up to 8 calibers and different loads at one time. Choose Ballistic Comparison under tools on the left. I'd be interested in hearing your opinion. As a note, I have nothing to do with this site. Just found it when I was comparing some loads for the 375 H&H to the 300 Weatherby.
www.ammoguide.com/
www.ammoguide.com/