Oops sorry i didnt see the publish date of this thread, this is a bit of a necro.
As long as they are made by decent companies using similar materials (all pellets are generally constructed of similar m[b][/b]aterials, ex plastic composites) the results for an accuracy rating will be almost all the same, the only factors you would need to worry about are the human variables in a test like this, but even then the slightest of difference can be made if you happen to get the occasional bad pellet or the location of the test. The distance of difference will be smaller than that of a centimeter, and even then triangulating shots is never fully accurate. You would have to fire thousands of shots of each to even get close to a result. Plus the grouping of shots will be greatly affected by the person shooting it. All in all, just get what is cheaper, because we all know that field conditions won't be stable enough to be affected by pellets that are a slight bit more accurate than the other competing brand of pellets.