I have found that the new this year Winchester M-22 runs great in my S&W15-22. I am up to 550 rounds without a malfunction in the 15-22. It also runs great in my Ruger 10/22 and my Ruger 22/45. Super-X in 40 grain loaded to 1255 fps also runs good. The "plated" or "copper washed" bullets work better for me than those rounds that have bullets with just a wax lube. The M-22 is in a 1,000 round pack. I bought my M-22 at the local Academy Sports for $45.99 per 1000.