.22 Mag shot shells for snakes?

[K_W]

I am going to the Kentucky wilderness this summer for a weekend hike and I would like to have something to use for snakes, should the need arise.

I have a .22 mag double barrel derringer, and some CCI .22 Mag shotshells. Will that combo be enough for snakes like Copperheads and Water Moccasin?

 

[6mm]

I'm not sure if the 22 mag will make a difference....

I have shot rattle snakes in the head with 22 shot and all it did was make them mad... 5 shots before getting a shovel to finish the job....