I've used loads (and loads) of amps over the years and once you get above a 300 (genuine) watt rating, with a reasonable speaker array (210, 112 or 115... heck some good 110 cabs will cut it) you generally have enough power to be heard over an enthusiastic drummer; especially in a rehearsal room.
However, what the guitarist(s) are doing, your EQ, room size/shape, cab positioning, drummer location etc can all affect how well you'll be heard. As others have said, you all need to be looking at ear protection, especially in small rehearsal spaces where you are playing with a drummer (cymbals destroy bass players ears). Get everyone else to turn down would be my starting point; the drummer playing at their comfortable level should be the loudest thing in the band, if you are drowning any of the drums out you are too loud... says the man who has been in many pitched battles with overly loud bandmates! LOL
Oh and I had reason to use a Rumble 500 combo at a rehearsal room the other week and it was seriously loud when it was barely ticking over, so I don't think the gear is at fault unless it is set up incorrectly!