I CAN DO BLUNT WEAPONS
Kills with Moira’s Crowbar in the main campaign
Resident Evil Revelations 2 – I CAN DO BLUNT WEAPONS Achievement & Trophy Guide
In the room that needs the rusty key will be a lot of spiders which are easily killed with the crowbar. You can kill all of them and reload the checkpoint. You will respawn in the room with the key nearby. Run back into the spider room and repeat this until you have all 50 enemy kills.