It is my understanding that the designated "accuracy" loads are nothing more than a function of the loads that develop the narrowest SD of velocity. No one actually went out and shot groups with this load. It was all developed in the the lab. But the potential for accuracy is there . . . . just a matter of whether it actually happens in your particular gun or not.

I was originally inspired to try RL 12 on the basis of the Nosler reloading manual indicating it was an accuracy load for certain bullets in the .308 Winchester. I discovered a real sleeper of a powder - one I use for lots of other calibers and now buy by the keg - that I might not have paid much attention to otherwise. So I don't think its a total waste of time to try powders listed as "accuracy loads" - but if they don't work in your particular gun, just move on to something else.