Back in the 1970's, a lot of us figured the coyote was designed to have something to shoot with a 6mm Remington. It was the number one cartridge I chamber in coyote rifles. Back then, the bullet of choice was the Sierra 85 HPBT and a lot of the rifles were built with a 12 twist barrel. Later on, with the advent of the low drag 105 to 107 bullets, the 8 twist was chosen. I still worked with 85's too. Barrel life was around 1100 rounds before accuracy started falling off. Some guys went through a barrel every two years. One guy, whose motto was, "as long as there's lead in the air, there's a chance", kept shooting as long as the running coyote was visible. He went through a barrel every season. I still have a 6mm Rem which I built 40 years ago. I don't shoot it much anymore, but it'll still take care of a coyote. WH