I agree with AWS that most 6mm bullets will work fine. My 6mm Remington loves 55 gr. Sierra Blitz Kings and anchors coyotes with authority at 3720 fps. Great coyote combination. I used a 58 Vmax one time in the 6mm that knocked a baseball size hole on the offside, but dead coyote on the spot. In a 6x45 I first began using 75 gr. Sierra HP’s and they did a good job, but i have since switchef to 70 gr. Sierra Blitz Kings. The HP’s seem to hold together better at 6x45 velocities, thus I have taken two whitetails with them. I am assuming the 75’s at .243 velocities will be very good coyote bullets. In my opinion, a 6mm caliber is a great coyote getter.