I have one that I like very much, it's an older Ruger 77 with the tang safety. I had a decelerator pad put on it right off, and have never thought it was uncomfortable to shoot. I've mostly shot the 250's and 275's in it. The Whitworth 375 is stouter as far as recoil. My gun is noticably heavier than the average 30-06 Ruger 77, I dont know exactly what the difference is, the barrel is a bit heavier, and the stock has very nice figure, so it's probably a little heavier than average. It also has the steel trigger guard and floorplate. Much of it is the way the gun fits YOU. I shot a Winchester model 70 in 300 Win Mag that I thought was much less comfortable than the Ruger 338.
When shooting anything potentially uncomfortable off the bench, try to set the sandbags or whatever you're using for a rest to a height that allows you to sit straight backed, not leaning into it. Leaning into a hard kicking rifle is distinctly uncomfortable, shooting off a tall rest, or sitting, kneeling, standing etc, not as much.
"Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-