Interesting article and it provides at least a basis for comparison between the various AI's. Clearly, the sharply tapered cases (250 Sav.) show the greatest potential gains vs. say the (.308 based) cases.
It surprises me somewhat that BJ is not more clear on the pressure differences between Ackley's data and some of the factory figures he (Jourdan) quotes. Given human nature, when some shooters get the hots to "improve" something, they tend to look at the highest velocities they can find and assume that their project will realize those gains. Unfortunately, they start stuffing powder in the case and chronying loads until they reach those figures. Often, those loads are too hot.
"She ain't blowed up yet" is not a sufficient indication of safe pressure.
Shooters getting all fired up over Ackleyfying something would be wise to include in their research, John Barnsnesses' recent article in Handloader titled "Pressure Guessing" As most modern (pressure tested) data confirms, the 4-1 rule of case capacity gains vs. velocity increases is nearly inviolate. In many instances, standard cases when loaded to safe maximums will shrink the gap between themselves and an improved cartridge pretty significantly (assuming the AI is loaded to the same pressure level).
This is not intended to denigrate Jourdan as a writer. I am simply of the opinion that his article is incomplete. An inexperienced shooter could possibly get the wrong idea about the potential gains from AI's if he were to take this at face value. In Jourdans defense, while some of the velocity gains that he quotes are probably not realistic, the article does give an idea of the relative merits of several of the AI cartridges.
JimF
