I had purchased a 22 synrod, did not clean it, stock settings, just shot it, with JSB 15's @ about 750 fps. They were OK not great. At 25 yards about an 1.25" in a 10 shot group. Then my order of JSB 18's came in. What a difference! At 25 yards pretty much pellet on pellet in a 10 shot group. At 50 yards I'm at about .5" with a 10 shot group. Sad thing is, my first synrod that I had was absolutely crap! Made me doubt my skills as a shooter, waste of money on pellets, air, time, targets. It was a nightmare. In terms of time frame, I bought my first synrod in the early fall last year, the new one about 4 months ago. I am pleased with the one I now have but I can not attest to the others. Good luck.