most deer in the area at 5 are in the 170 to 180 so i think he needs a bullet.
If 170-180 inch deer are on your property, why even worry about this buck. Shoot a 180 class. Plus, 50% of the genetics come from the doe and bucks roam during the rut.
Killing a deer because you think he's an inferior animal is insulting to the deer and it's not hunting in my opinion. It's half-azz genetic engineering.
And you should let your girlfriend shoot any buck she wants. Whether it's this one, a smaller one or a bigger one.