Just finished zeroing my Rock River at 100 yds this morning. 18" barrel, .223 wylde, with a vortex crossfire II 4-12x on top. I was shooting some American Eagle .223 50-grain Varminter rounds. Overall I'm pretty pleased with the results, as I was able to achieve 0.5" groups at 100. This was prone, with a bipod. The only thing was the wind seemed to have a pretty significant affect on the 50-grain bullets. When the crosswind would gust to about 7-10 mph I was off to the right about an 1-1.5 inches. I'm not a veteran of the .223 so is this fairly typical? What are your favorite varmint loads? For woodchucks and/or coyotes?