Yea but neither of them travel at 4300+ FPS. Although they do come close. Dale http://en.wikipedia.org/wiki/.223_WSSM
Dale,
In regards to the 220 Swift & 22-250................true. One note though, if used for Woodchucks, IMO there is not a factory caliber from .224 down that tears up Woodchucks more than a 220 Swift / 22-250. In particular a 50 grain V Max at about 3800fps.
In fact, they tear them up like a .243 with light stuff. Twenty,Seventeen calibers, .223's etc. really don't come close to the carnage.
I have noted this for some time. It was again confirmed this summer on another website with a thread / contest about woodchuck carnage. The 22-250s, Swifts & .243's tore them up the worst. Larger calibers were also used but, they lacked the explosiveness.
I don't care for the muzzle blast these days nor find it sporting for the majority of shots inside 300 yards. But, the Swifts and 22-250s really make good woodchuck medicine and are often extremely accurate in a quality bolt action.
Now some here are using the custom 1/7 - 1/8 fast twist 22-250's and very high BC bullets for there long range / low recoil long range Chuck rifles
Now...........that will chew up a barrel