The .223 will make 1000 yds depending on the barrel twist and bullet. If you have a 1-8 twist and can shoot the 70 JLK's it can do it. I have done 650 with a 50 grain BT and think I can do 700 with it in perfect conditions but at that range there is no excitement when you hit a prairie dog at that range. They just fall over. Of course the hit gets you excited but no red mist.
The big question is what is the gun to be used for. That will have a lot to do with the scope you use. I'm using a older 1" tube VX3 Leupold in 6.5X20X40 AO that has been boosted by Premier Reticules to do my long range shooting with my .223 and it works great. It has had the tall turrets put on it so I can dial up my ranges and I"m using Leupold 20 MOA base and 1" rings on it. For sure its not a running coyote gun but for targets that don't move much its great. For the longer distances I use a Leupold 6.5X20X40 30MM tube with the turrets and 20 MOA base which gives me a lot more up down to it to reach the range your speaking of.