The subtle point in the above posts, is it really depends if the bullets are jacketed or cast. If they are jacketed bullets you should not shoot them as loaded, as the possibility of sticking a bullet in the barrel is very high. If they are cast bullets (lower friction), then the possibility is lower, but is still a possibility. I wouldn't shoot them rapid fire, as you would want to check the barrel (or target) after every shot to make sure the bullet left the barrel.
I would probably pull the bullets, use them again, and either discard the powder, or increase the load up to 6 grain. Don't throw the powder into a can with other powder. You will end up a few cartridges short in the end to load up with something else.
If you do stick a bullet, search the threads for all the tips on how to get the bullet out without damaging the barrel.