simonl

I have a wide range of calibres and do lots of fox control. I too started with 17 HMR. 117 foxes in my first year with it. I now prefer my 243 over my 223 & 204. Trajectory wise there's not a fat lot in it for typical fox ranges between most calibres, but the devastation from the 243 is pretty brutal: They are all instantly dead. Very dead.

if you can't remove all sources of food from the area then forget baiting

Buy 6 traps. Leave them in the shed for a few days, near the perimeter. Then bait them with peanut butter, but do not set them. Then set them all one night. Other option is a dustbin (with optional water in the bottom) & a tipping platform, baited at the end. Use a small magnet to add a sudden (not progressive) tip.

So do you feel that load development might be unnecessary? i.e. Pick your required pressure-safe velocity & then just tune harmonically?

It listens for the bang IIRC. It'll never manage to be very selective about whose bullet it's tracking. Will probably tend to pick up the signal from the bullet with the biggest/flattest tail (eidt: which is most perpendicular)

You wouldn't develop a load with one mod & then change it... that's what you're doing in essence. It's the sole reason I haven't bought one.