When checking a magazine for ammunition, if the gun is at low ready or high ready, you have to adjust your free-look to see how many rounds you have left, or pull the gun back up to compressed ready and check again, as the player will keep the magazine close to where the gun is.
My suggestion is to have your player bring the gun and magazine to eye level when checking your magazine.
I would also like to suggest the same behavior when performing a press check.