No money for tweaks means it has to shoot out of the box. This eliminates quite a few players.

No rangefinder eliminates long range hunting for me. No more than 450 yards, and that only in perfect conditions.

A budget of $400 isn’t much for a good scope. I’d much rather reverse your order and go $700 for glass.

But, playing along:

Browning X-Bolt Stalker in 6.5 Creedmoor
Used Zeiss Conquest of some sort in Talley LWs
Barnes Vor-TX 127gr LRX

I’d also consider the Tikka and a mid-range Leupold if everything has to be new.

I also really like the Nosler 142gr ABLR an awful lot but the lack of a rangefinder negates a lot of what I like about it. Plus, bison (!!!!!) calls for the deepest penetration and Barnes is unmatched.

What could be a sadder way to end a life than to die having never hunted with great dogs, good friends and your family?