i have a bit of a conundrum which i'm hoping a few of the more experienced reloaders may be able to help with. have recently purchased a new .223 (remington sps tactical) for fox shooting as i quite liked the idea of a short more manoverable barrel especially when shooting from inside a truck. the barrel is 20" long and has a 1 in 9 twist rate. when i originally tried the gun i used 55gr fedral's which gave me a 4" group so i was back to the shop were the chap said try some heavier rounds as the 55gr may well be coming out to fast and he gave me some 79gr target ammo which shot a 1/2" straight off. now the rifle has gone off to be threaded but does anyone have any ideas what the lowest weight bullet the rifle will like (dont forget its a foxing rifle so it neededs to be as flat as possible) or is it a case of just buying a few differnt weights and giving them a try which is going to cost me a arm and a leg and take for ever.