DFA actually hasn't done any serious bolting. Replaced a few back in the day with a homemade hand drill, but holes in basalt took anywhere from 45 minutes to an hour and a half. Bolters DFA has seen or known favored the Bosch Bulldog, a Ryobi gas-powered beast that sounded like a chainsaw, and some Hilti monster.
You really ought to post this query on smithrock.com, as Ryan Lawson has got beaucoup drilling beta. He might even have his bolt-guns up for sale, as he had mentioned such a while back.
Here's to more bolts everywhere!