Originally Posted by north of 53
If you only have a 1:12 barrel and you are only going out to 500 yards I would just stay with a 223 and have some barrel life. If you want to run bigger case size for a 22 get at least a 1:9 or better yet a 1:8. A good 223 should own the ground out 500 yards. The extra rounds you can shoot to get trigger time and practice will make more of a difference than the gun will.
I shoot a .223 Remington on coyotes a lot of the time around here. We get some pretty good sized dogs, and 35lb. ones are getting to be rather common anymore. Most of my hits have been under 300 yards, but have taken a couple dogs close to 400 yards. To me anyway, the .223 is starting to get marginal after 400 yards for that clean one hit kill. At 300 yards it drops them like a rock. Looking at the ballistics chart, and using the data from my Remington, I see 280 ft.lb. of energy at 500 yards (3200 fps .255B/C), and about 390 ft.lb. at 400 yards. But 548ft.lb. at 300 yards. Now had we been using the 22 Jaybird at 500 yards with the same 55 grain bullet will give you 471 ft.lb. of energy (3900fps), and 850 ft.lb at 300 yards.
I like the case design of the Jaybird, but would like it a lot better in 6mm, and a 1:8 twist barrel