You know 8mm this is a topic that we rarely discuss but has serious merit. I don't know the answer. I do see alot of guys that have 20" 338win mags, and gets great performance with >200gr bullets. But the 338 RUM will start degrading quick with less barrel length than a 26".

I would like to have me a handy elk rifle in a 338win mag with a 20" barrel.