I agree with J, I don't care for the videos of women and kids given guns they aren't prepared to shoot.
The ones shooting T-Rex are different. Those mostly are guys used to shooting. The T-Rex shoots a 750 grain bullet @ ~2500 fps. BTW that range is in Saeed al-Maktoum's house in the UAE. He owns the Accurate Reloading website. He's a really nice guy, very generous. Everyone on AR that has met him seems to think a lot of him.