When it comes to rolling ammo with small charges and speeds, I recall an article years ago in an issue of Shooting Times, I think, that attempted to reveal some of the factors that went into the the making of precision rimfire target ammo. As I recall it was Eley 22 LR ammo commonly used in biathlon competition. As I also recall they had worked out a couple of very significant factors which affected the accuracy of the finished rounds. One was the priming process , the distribution of the compound, and the consistency of the quantity. The other factor involved the effect of ambient conditions on the powder when the rounds were assembled, perhaps especially humidity. By controlling for these things, they had managed to create a product which earned a reputation for a higher degree of accuracy than other manufacturers had at the time.
Thankfully, Remington still maintains their line of Golden Bullet ammo as a baseline, so we can see how far the world of rimfire ammo has come.
