I own a .223, and it is a good medium range caliber, but it is not much for true long range. The bullet drops off fairly quick compared to a 22-250 or a 220 Swift.
Ranger, your 22-250 sounds badass, my 223 is a Ruger M77II with a trigger job, stainless barrel which i had a matte finish on. It is a tackdriver with 55 gr. ballistic tips.
Sounds like these kills are all 100-150 yards, hell, i can shoot my .54 caliber Hawken blackpowder at a 100 yards! This guy is no expert, or atleast has not proven it yet.