I'd also eliminate the possibility of it being caused by a metal feeder; there have been a lot of lost toes and hurt beaks from them this year.
Incidentally, I'm a HUGE believer in Clotisol brand blood stopper. I got my first small bottle from a vet when my African Grey hurt her beak and tongue. It's water based, can be used on beaks, is non-toxic, and really will stop even large 'bleeders' immediately. If it gets thick in the bottle, add a little water. One small (4 ounce?) bottle lasts for ages and ages. And when you have a beak injury, or a head injury (which bleed profusely) it's nice to have something that stops it immediately.
It's SO effective that we used to use it on our mollucan cockatoo who we bought as a bahavioral self-mutilator and would bite his own chest. That was a lot of blood, and clotisol is what the veterinarians recommended that time as well. Of course I already had my own bottle.