I've found that blindfire is usually not a great idea, for two reasons. One, it's usually unaimed, and two, you're stuck to cover. The latter is probably the worst problem, the former just makes it often a waste of ammo. If you're blindfiring, you're also a big target for a good penetrating shot too.
I've found it far more effective to quickly strafe across an open doorway while being ready to hipfire. That way you're only exposed for a very brief period, during which you're a moving target, and you can also quickly move out of the area where you might get hit through the wall. If you see an enemy, then you bank a grenade in there off the wall, and rush right after the blast while they're still disoriented/scrambling to clean up survivors.
Blindfire is usually a bad idea/waste/ineffective in real life, and it is in RO also.