Have a mosin with long range scope attached on it.
Go into your inventory and drag your mosin with LRS attached on it into your "item bar" on the bottom of your screen on, I don't know, place ONE.
Now go again into your inventory and drag only your long range scope onto this bar at the bottom of the screen. But on another place then "ONE" (e.g. TWO).
NOW...
Press ONE to arm your mosin with LRS attached on it.
Press TWO to only arm your LRS.
Where is the problem?
Run very long time and try to use your mosin - impossible because you are breathing - instead of using the mosin, you can now arm only your scope by pressing TWO and the cursors is totally quiet.