I would work on the idle a bit more. I like to think of it in the idea that you are breathing and how would move holding the item. In this case the RPD is likely very heavy and you would be breathing slower standing still holding the item, this would result in longer down frames as the weapon moved with an exhale and longer up with an inhale.

I also look at this in the idea that the character has infinite stamina (this would be different in a game w. stamina) so you don't worry about what it might look like in the case that your character had just finished running.

Overall pretty nice though, keep it up.