I have used 3 doubles quite a bit.
A 450 No2, a 450/400 3 1/4" both British and a scoped 9,3x74R.

I like them all, and in truth would not like to be without all 3.

My 450 No2 is my favorite rifle of all time.

The 9,3 Chapuis is one of ther best hunting rifles on the planet, under 40 cal.

I recently had my 450/400 scoped with a 1.1-4 S&B in claw mounts.
The 450/400 cartridge may be the best for the modern sport hunter.

IF, I could only have one double the scoped 450/400 3 1/4" would be my choice.

With 300gr Hawks for small stuff, and 400 gr Woodleigh Softs and Solids for everything else, it can do the job.

I have killed deer, pigs, 2 caribou, black bear, baboon, warthog, cape buff, bull elephant, and lion with it.

But I sure would miss the other 2.