Bought a new bow today, 06 Bowtech Allegiance

It chrono'ed at 301 pulling 65 lbs. 29 inch DL and arrows weighing in at 347 grains.

The shop owner told me that these arrow weights would be fine for taking pigs, white tail deer, coyotes etc... But I would need more mass for bigger game such as elk.

If you have arrow speed with a good sharp broadheadand you get a pass through is'nt the kill due to the vitals being punctured?

What is need for more mass? Isn't it all the same?

50mass X 30 speed = 1500KE is the same as 30mass X 50 speed = 1500KE