I have a friend BW who swore by Kahles- on his 270!!

He switched it to his 338 for an Alaskan hunt and it promptly died after one box of shells,and then he swore AT that scope!!I think he finally used a 2x8 Leupold and was happy with the scope function.

Personally,I don't think kahles is made to take the recoil of rifles stouter than a 30.06--