This might be true for you but not for everyone. I have a lightweight .270 win that I no longer shoot because of recoil. I bought a heavier rifle in 7mm-08 and love it. For me, the 7mm-08 is the perfect do anything round. I wouldn't own a 300 win mag if you gave it to me. Each person is different as to what they are comfortable with. Ethical shots are about shot placement and staying within your comfortable range. I'm a bowhunter so I'm used to shots inside of 40 yards (10 yards is better!
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). With a rifle I don't like to shoot past 200 yards. Everyone is different.
If I was going on this hunt I'd bring the 6.5.