Excuse my ignorance, but is a .223 bullet the same bullet used in 22-250 reloading? Book says a .223 bullet has a diameter of .224 and the 22-250 has a bullet diameter of .2245. Does that difference matter?
Yes, a .223 Remington uses the same bullets as a 22-250 Remington.
.224 is the correct diameter for either. You just need to be careful of the twist rate. Most 22-250 barrels have a slow twist and will not stabilize the 60 grain or heavier bullets due to their length.
.
