Quoted:
The .50 doesn't even come close to the .338
+1
Long time 338 shooter here. For me, stock design has a lot to do with felt recoil in big bore rifles. My first 338 was a stainless Ruger 77 with the old "boat paddle" skeletonized synthetic stock. That rifle beat me so badly that I almost gave up on the caliber. Then I traded the Ruger for a Remington 700 stainless/synthetic mountain rifle in 338. This is a lighter rifle, but the superior stock design makes it much more comfortable to shoot.
These days I use something between me and the rifle butt when shooting off the bench. A PAST recoil shield, a sandbag, a rolled up towel, anything that will provide some cushioning. If I don't do this, I quickly develop a flinch with the big bores. I've shot the 338 many times in a t-shirt in a hunting situation, and if it kicked at all I don't remember it.
My youngest son has a Weatherby Ultra Lightweight in 30-06. That thing is brutal at the bench, worse than my 338. Just sighting it in is all I want with that thing. But as he says, none of them kick at all with hair in the scope.