this will be a little long winded as i was blessed with many opinions haha.
As a handloader/ hunter I am very familiar with amunition components, terminal energy theory, sectional density, ballistic coefficients so on and so on, and the end result of changing each component, which i have...
I have personally taken 5 Mountain goats at anywhere from 15 yards to 300 yards with my tikka t3x lite 6.5 x55 and 143 gr eldx bullets. patience and shot placement are key. i try to go high forward lung, halfway between the top of the hump and the elbow if standing, trying for the lung/shoulder...