I'm sorry......all those guys are trying to lead astray.
What you need is a great gun. One that's easy to kill with.
There's this one very light recoil round, it called the .458 Lott, it's a great gun for kids.

Shot one when I was two. (Just Kidding in a very corny way.)
Really, stick with your .270, it's good.
If you want to die,try to fire 60 rounds through a .460 Weatherby.(I think there's such a thing.)