To make it, you need to keep the bullet super sonic.
Its have no problem keeping the 200 SMK @2850 FPS. (thats what my Model 70 300 WM 1000 yard rifle likes)
If you crunch the numbers that would be a hair over the speed of sound, so yes you can do it.
If your sights are bottomed out at 200, your gonna need about 72 min of elevation. Winds gonna be fun.
But heck yeah, why not. You can build and shoot a 300 Win a lot cheaper then a 338 L or 50 Cal rifle.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071