Re: 300 wby
1st - Start shooting good Sub-MOA at 100 yards.
2nd - Move to 300 yards.
3rd - Move to 600 yards if you rifle can do it. If it can't get a precision stock bed it and maybe replace the barrel.
Then continue 100 yards at a time till you get to 1000 yards.
There is more to shooting 1000 yards then pointing a shooting. Its a lot of practice, precision loading, time twecking your gun, etc. The 300 wby is a good one and the vanguard is a good gun so with some work and effort you can get there.
The difference between people who do stuff and people who don't do stuff is people who do stuff do stuff.