Have been flintlockin for a long time and I have never saw a deer spook because of my leather bag. They might smell it if you just treated it some kind of smelly stuff. I think it boils down to what works for you.
I would think "Leather" bags on hunts would be beneficial because of the salt used in the tanning process..
Wouldn't you think that leathers would naturally give off salt scents? hmmm makes ya wonder...
Democracy is two wolves and a lamb voting on what to have for lunch.
Liberty is a well-armed lamb contesting the outcome of the vote.