The reason they probably confiscated the ammo was because you are limited to 50-100 rounds per person if I recall (and two guns in one case). I have flown with more, but since you had loose ammo they have to open it, then once its open its 100% by the book. The TSA sends fake passengers through at times to make sure the employees are doing their jobs, so if they have your bag open for loose ammo, they can't leave 300 rounds sitting in there. Now as for the knives I don't know why.
I worked for TSA at the very beginning before quiting. They are good people its just boring and we need something to do, so the second someone gave us lip it was on like Donkey Kong. You wouldn't believe how many people wuld give us crap at the the very beginning. We confiscated a ex-airline employees LOADED handgun (ya, he was fired the day before) as he was trying to go through security to board a flight! Its a good thing that since we all knew this guy somewhat, that we didn't just let him go on his marry way. Non of us knew he had been fired at that point. Of couse when that happens it gets sent to a LEO and then since its an airport everything is Federal so it gets taken care of and its all hush hush, but we get no respect for that. I mean, Yes, I understand that babies are not going to be terrorists, but if you ever watch the news people are sick and will use anyone to smuggle. And since we have laws that say we can't "profile", middle eastern babies cannot be singled out. Its all common sence people, until the left stops bitching about racism every 5 seconds, you have to put up or shut up.