AL, I've had a pile of 338's (was a cartridge I doted on for years). I had at least three shortened to 22". Personally I wouldn't go less than 21" or more than 23" so 22" always struck me as just right. Plenty handy, but not overly obnoxious in the noise department.
NOISE will be there in a 20" tube and I'm personally past the age I want to do that to my ears. When I was younger I was a carbine nut. Still am really, but some rounds lend themselves more to 20" (and less) barrels, not because of velocity loss, but because of noise. The 338 WM isn't really one of them IME.
At least that's the way I see it...
