Having shot and loaded both cartridges in various bullet weights, the 338-06 will generate more felt recoil all of the time. But it's not gonna scramble your brains....
I never owned one in 18", but I'd opt for a really good pad for that 760...
If you can afford to do so, I'd leave the carbine alone and stuff it with 165gr partitions and buy/build a 338-06 with a 22" to 24" tube....would be a great rifle combo!
If you like velocity, if you load the 338-06 with 180 AB's for example, you'll drive them faster than from the 30-06...
