If there were no hidden changes it is linear (if thats the right word for it) increase by range. I think it translates to 0.5% damage every 1m to 12% at 24m.see below
//EDIT:
Apparently it is not linear (i guess it was changed or I did wrong test back when). Now it is 3% at 10m, 7% at 20m and 12% at 24m.
Awesome thanks a ton. Yeah I had read some thread where some said it changed and then some saying how unfair the 40+m was back int he day since they switched snipe to less distance made almost no attacks effected by it. Glad to see this is not/no longer the case.