In my Tikkas, R15 and CFE223 have given the best results with the 120TTSX. I use a mag primer with the CFE, BR2 with the R15.
That said, has your rifle ever produced what you would consider a good/reasonable sized group? Some barrels are just duds.
You're basically living in hog heaven. Unfortunately it's just about 100% private land. You usually have to "know a guy" that knows a property owner. There are guided hunts in the area if you're looking for that. Your other options are the fish and wildlife management areas. Not loaded with...
"Sometimes good" is usually a form issue. Your form has to be spot on and consistent shot to shot to achieve reliable bareshaft results. Short draw, probably stiff reading. Long draw, probably weak. Pluck it, who knows what you'll get. If you really want to see what the arrow is actually doing...
This may be of use to you..
https://www.usconcealedcarry.com/resources/federal-ccw-law/federal-minimum-age-to-purchase-and-possess-handguns/
Federally it's legal. You'll need to check your state laws as well. Idaho is 18, not sure on MT but I'd be surprised if they weren't also 18 for...