Re: 17 Hornet
cbf is correct. It will occasionally work to 300, but under 250 is more like it. It will NOT explode a groundhog. More than likely, you won't get an exit and will have a hard time even finding an entrance hole.
Like cbf said, the 17AH is it's closest related cartridge, and the 17AH has been around for years. It is a great little round, especially for predator hunting. Works great on foxes, coons, etc. that you don't want to blow huge holes in the hide. Handloaders will enjoy it. Only about 10 gr of powder to get 3700 fps, good 17cal bullets available, etc. It's going to be very popular.