depends on the brick, some are hard, some are soft, noral hammer drill with a sharp quality masonary bit will do most for typical 7mm plugs
is your hammerdrill working properly, good vibrations and all that (fast speeds with them seem to work better too)
I used to live in a property that had a particularly hard cement "plaster" on the walls. I used a 705W hammer action drill to drill a 7mm hole in the wall. After about 7 minutes, the drill bit bit started glowing red. Admittedly it wasn't a new bit, but it had only made a 2mm dent. On advice from a friend, I borrowed a SDS drill. It took 7 seconds to drill the hole.
I went out and purchased my own one. Two of the OMG items that I regretted not buying years earlier are SDS drills and oscillating saws.

