One is a standard hollowpoint the other has the post inthe middle(HydraShok). As a matter of fact I have the 230 gr HiShok(standard hollowpoint) loaded in my carry gun now because I got a good buy on several boxes. It sells for half of what HydraShok does in my area. Velocity is the same, it just not the "premium" line, not nickle plated brass but is cannelured.
The Hi-Shok bullet is sold as part of the "Classic" line from Federal. 45D is the 230grn JHP Hi-Shok. It's good stuff. In fact, it's really almost the same as Hydrashok without the post already plugging up your hollow point. Oh, and as was already mentioned, it's a heck of a lot less expensive.