I have a remington donor short action and McMillan A3 stock.... and no idea what I want to build for a varmint gun.

What are the pros and cons of each and of the Ackley versions? I will be handloading and the goal is to push a medium weight bullet, fast. Thinking 55-62gr Amax or NBTs.

Thoughts on best barrel for this this? Length/contour/twist?

I will not be 'burning it up' over a prairie dog town. Mainly shooting yotes and foxes and any small hogs that might happen past.