I wouldn't shoot the cartridge with the dented case.
If that's a result of the feed lip on the magazine, then you are overloading your magazine, either by number of rounds, or based on spring tension. If a metal magazine, the lip on the magazines may begin bending. If metal or polymer, I think you are over compressing the springs in the magazine and will likely need to replace the magazine springs early. If you aren't counting how many rounds you are loading, you should be. You might be jamming 61 rounds into a 60 round magazine. Not a good idea. If you are loading 60 rounds, and the feed lip is denting the case that badly, then I would download the magazines to maybe only like 55 rounds.
As far as the beat up bullets, shooting them isn't a problem, but I question why they are so beat up. Something going on with your feed ramp? Is the gun cycling properly?