Man vs. T-Rex: What Gun Would You Need to Beat One?

Testing the effectiveness of various firearms on a T-Rex, from the smallest
handgun (.22 pistol) to the most powerful rifle in the world (the 950 JDJ,
which shoots a 2400-grain round that produces 30,000 foot-pounds of muzzle
energy and 300 pounds of recoil):

https://www.youtube.com/watch?v=7Pf6E8yjMAI&t=2s