I recently came across the 6x45 while browsing the web. Correct me if I'm wrong but this seems to be the perfect coyote caliber. I already have an AR .223 and a bolt 243 so it seemed like I had my bases covered...until I came across this cartridge. Pretty much a low velocity .243 with cheaper brass and less powder. Is it really worth it to spend money on a new upper? How well does it do on coyotes when trying to save fur?