There is no best caliber or bullet for elk/moose. Dozens of calibers and bullets make this job perfectly if you hit on right place from right distance.
Do not have experience with 338. Was once close to buy for Africa but end up with 9,3x64 brenneke (293gr bullet). Familiar also with blood on eyebrow (twice) using high recoil guns. Main reason for that is too close scoop and wrong body position. Using 9,3x64 caliber for Africa hunting and reason is simple. If you pay 500$ or more for trophy there is no room for mistake and big caliber give some advantage. But to be honest largest Kudu bull take down with 30-06 Norsler AccuBond from 100yrs and it drop down same place where I hit it...
Newer used 9,3x64 caliber for moose/elk as in my opinion too large. Twice used for wild boar. They drop down is same place and both time damage was huge...
Therefore my favorite for moose/elk hunting is 30-06 Balzer93, bullet 185-200gr Lapua Mega as reasonable caliber and mild recoil. Have also 308 and 7x57 and also this calibers work well. Important is how gun suits in your hand and how familiar you are with that...
Every man like gun and caliber what they have...
