My Cherokee has a 1/48 twist from the factory and it is a great shooter with .310 Hornady round ball,10-15 grns 3f -Goex,.015 pillow tick patch,mink oil lube.
I have never considered using a heavier load on Squirrels this one tears them up bad enuff need to try for head shots unless you like the Brains for eating,as some people love them.
I have been told by some that have tried this ,with a thicker patch they can still get good accuracy with up to 40grns powder, witch would probly be a good close range Coyote load.