I use a .25. I use Altaros 50 grain slugs at 857fps. 187 bar, 1 x .2mm jet, 450mm barrel, shogun moderator. Almost 82 fpe, 8-10 good shots per fill. Planning to do a ballistic gel test in the next few weeks to see what I can ethically harvest with this, but Coyotes would not be a problem.