The longer the barrel the heavier it will be to carry, unless you're building a LRH rifle. I was never a 18" barrel fan but the do kill game effectively, and scientifically theres very little noticeable difference between an 18" barrel and a 22" barrel(velocity wise). May I suggest the 22" barrel for your sheep rifle to keep the weight down. A Hart or Lilja ought to work fine and give you excellent accuracy. And good luck, let us know how it works out. I think the 260 Rem, the 6.5-284 Norma, and the 284 Win are finally achieving the success they so richly deserve as short action LRH ctgs, we just need to get the factories to put out some rifles for us in them 3 cals to keep the costs down.