... I often recommend a .30-06 - to the point that a .30-06 is what I buy for wedding presents for sons-in-law. For Daughter #1 I recommended a .308 Win.
The problem with "deer hunting at longer ranges 300+ yards" is that you never know at what range you will actually be shooting. On one occasion I anticipated a 300 yards shot if I was lucky, 600 if not. Instead I had an opportunity at 25 feet.
300 Weatherby solves all problems. Someday you'll come to the right answer.
My .300 WM does everything I'd ask a .300 WBY to do. If the .300 WM won't do the job I'll take my .338 WM over a .300 WBY.
Frankly, I'd take another .30-06 over a .300 WBY, and I already have three.
