When I first tried Nosler 70gn RDF projectiles in my Howa .223, 24", 1:9 twist, fluted bull barrel, I had not long started reloading and certain things that seem obvious now I've learned about them were not then.
One of which was pressure signs.
I worked up the most accurate load, which allowed 2.5 - 3 inch groups at 400 and was feeling pretty smug about it when I came across an article on recognizing pressure signs when reloading, by Greg Dykstra from Primal Rights.
After reading the article I went hunting for any signs on my brass and found that these most accurate rounds loaded at ADI's maximum recommended 25gn of 2206H, were seriously cratering the primers.
I tested downward in 0.1gn increments until there were no more signs of pressure at 23.9gn, but the accuracy had completely degraded.
I then decided to see if going any lower might help, and tested down to the minimum of 23gn with depressingly deteriorating results.
The only conclusion seems to be that my 1:9 twist can't stabilize them at safe pressures, meaning they are, for all intents and purposes, useless in my rifle.
I would appreciate any opinions.
For those not familiar with the article:
http://www.primalrights.com/library/art ... g-pressure