Not particularly.
rifleman takes damage while scoping, his charge will still be same
So, no change from how things are now?
but after he scopes again the charge will be faster
By "after he scopes again", are you trying to suggest that when he takes damage he stops scoping? It's really unclear.
even if he already took damage while scoping
"even if"? You already said this happens when he takes damage while scoping, so this just sounds redundant.