Tell him to contact these guys, specifically Kenny.
https://www.dpgunworks.com/
He will re-barrel that sucker with a far better barrel than will come off of Ruger's machines, and his work is second to none. He's also pretty close by if I'm not mistaken.
I remember it well! I'm going to have to find a way to source some ammo, I can't seem to find any good ammo. I have plenty but I'm not going to shoot what I can't replace.
Based on my research, the Tikka is an amazing rig straight out of the box. I know the gear can do it, I just have to get the Indian up to speed about the arrow.
It's not a rule, by any stretch of the imagination. It's simply my recommendation, I don't begrudge anyone who wants to disregard it. My only intention is to save others some grief, by all means use what you know will work for you.
I wouldn't advise trying to run any soft-point bullet in a 308 AR, it may or may not work out, with failure being more common than success. It has to hurt to watch good handloads be ruined by a rifle that's designed for hard-pointed ammunition.
Wilson Combat is notorious for an undersized gas port on early run barrels. You'll end up drilling that gas port size up. Fortunately, it's not too difficult.