Originally Posted by hanco
You would really like a 6.5-06

He would, I like my 6.5-284 which is a ballistic twin.

But, the OP is wanting to fit a 9 twist .223 take off barrel, chambered for a high stepping .224 round.

With that, I'd still recommend Elk's 22/6mm suggestion. That round will run with the .220 Swift and feed a lot slicker thru a bolt action.

After a point, you get into diminishing returns with the .224 bore., the 6mm case being about right, IMO.

DF