I think it will work, but ultimately it depends on the type of rock as to how long it will take. In my experience here in the Ozarks, where it is very rocky, the demolition bar is far more useful than a gas powered auger. The jackhammer sounds like a good solution.

I feel for you,I think that digging in rocks is one of the most frustrateing jobs.How deep do you want to make The holes?
If your recommended hole depth is 4ft,You can get away with 3 ft because your soil does'nt hold water your chance of heaveing is'nt a problem.Or if it's just a few that you can'nt get deep enough you might cement them in.

Good luck

lp

What kind of posts are you wanting to set in the holes? If wood, I would advise you to set them in concrete, or you'll be doing this all again when the posts rot. Unless you're using something like black locust for the posts.

I have rocky soil, too, and it was such a pain. All I had was a posthole digger, a shovel and a bar. And no John Wayne to do it for me, either.

Sue