If he wants to use a .270, there's nothing in the world wrong with it. You said he's a decent shot. Define "decent". Is he capable of MOA accuracy? Is the rifle? My preferred shot placement is 5" behind the shoulder crease, 1/3-1/2 way up from the belly line. Don't overthink the bullet construction thing. Only bullet I wouldn't recommend is the Winchester Ballistic Silvertips. Those things make a real mess when they hit ribs. Fist sized holes from my '06. NOT an exaggeration.
Have never shot a deer in the neck. But I'm going to this year to see how well this works. But my understanding is they are "bang flops".... We shall see.
Have never shot a deer in the neck. But I'm going to this year to see how well this works. But my understanding is they are "bang flops".... We shall see.