Re: Drawing of a 6.5x55 AI reamer
This is the quote from the article you listed above regarding the swede.
For the next best gain, number four in the chart provided, I am taking my writer’s prerogative to show a standard cartridge that Ackley did not work on, but is now known as the 6.5x55 BJ Ackley Improved, the initials being my own. In the early 1990s I thought the standard 6.5x55 Swedish cartridge would show nice gains if it were improved as an Ackley. Little did I know that Ackley never did it. But to make a long story short, I got busy and copied the Ackley design into the 6.5x55, with a great deal of input from Dave Manson of Manson Reamers (PS advertiser). With the 140 gr. bullet the velocity gain is 13.7%. Standard factory velocity is 2550 fps, while the 6.5x55 BJ Ackley gets 2900 fps. This is another Ackley cartridge that I have used extensively for hunting, and I have heard from several readers who use it in long range competitive shooting.
Do you know any further info regarding this quote? Were the pressures kept the same for the AI load as the factory loadings? The swede is a bit of an anomaly because many of the factory and hand-load recipes are loaded to low pressures of around 45-47k psi so they can be used in the older Mauser style actions of the past. If the pressures were increased for the AI, which is possible as I am sure it was done on a new, stronger action, then those numbers likely aren't accurate.
I think the listed velocity of 2550 is a bit low even for the lower pressured recipes. But if the pressures remained constant throughout the tests that is still a pretty impressive increase, especially when you keep in mind the other benefits of the AI chamberings like case life, less case work, etc.