I've found the 200 gr. wide flat point GC bullet used by Double Tap to be excellent. In my 10mm, loaded over 9.5 grs. of AA#7, they shoot through three 2.5 gal water containers. In comparison, my .44 Magnum with full power 240 gr. Hdy XTP HP's only penetrate two of them.
On top of that, they are very accurate, and shoot within 1 inch of my 180 gr. XTP loads. E