You are nerfing the Mini Scout the wrong way.

Here are the patch notes taht are relevant:

This has to be a joke by someone who does not play the game to understand what makes snipers frustrating to the recieving end and what does not.

The mini scout is the one rifle that does not have a sweet spot and relies on one to have the luck or skill to land a headshot, especially when a follow up shot is not likely.

This will only make its already low pick rate even lower (most guys like their cheap sweetspot kill and low drag rounds)

If you wanted to make the Mini Scout be less good at beyond 150m, you reduce its V-E-L-O-C-I-T-Y, to make it harder to land a shot at someone who is not completely still at a distance. In older BF games you could change the gravity acceleration of different guns to change how their rounds are affected by long shots.

Now the Mini Scout will be completely dropped for the ELR-40, M2010 ESR (the most used SR in the game) and any other SR that actually has sweetspots bellow 150m or beyond.

When making balance decisions you are supposed to think hard about how things work in practice before throwing stuff at the wall and seeing what sticks and leaving it there for months to fester.

Edit: 
Alternative nerf that could work for every sniper rifle in the game:
Make it so Snipers have to stay still for more hundreds of miliseconds  before they can get back their full accuracy. This will make them have to stay longer exposed to take a good shot.