LEE dies and Speer bullets?

[Jack]

As I recall, when Lee introduced the factory crimp die, Lee ran some ads saying that factory ammo was crimped, and doing so with Lee's new die on all your loads would increase accuracy.
Speer ran some counter ads suggesting that the Lee factory crimp die shouldn't be used with bullets without cannelures, as the factory crimp die would deform the bullets, reducing accuracy.
Which is true, I can't say, but I think that's the source of the watering contest.