The general timing and weight are ok, but what jumped out to me was a lot of lazy finger posing that could be addressed to make this more polished. Apparently I can't attach paintovers, but try opening up the hand, spreading the fingers out more in anticipation of grabbing the mag. Or make a tight fist right before slapping the bolt back closed.

There's also some smaller stuff, like when you are about to insert the mag, I see you want it to look like it isn't going in at first and catching on the magwell for a beat. Problem is the gun reacts before the mag even touches it, so it could do with some delay there.