Greetings again all,
Thanks for all the suggestions which I will follow up. I mentioned earlier of rules that allow estimation of possible velocity. The rules were developed from chronographed load data and written up by John Barsness in the June 2006 issue of Handloader. The rule for comparing, say the .270 and 6.5mm06 and the 130 grain projectiles was that possible velocity, in cases of equal capacity, varies by 25% of the difference of projectile cross section area. This works out to 2.5% less velocity for the 6.5 from the .270. This works out to around 2,950 fps in a 560mm barrel for the 130 or 129 grain projectiles. None of the Hodgdon data for either AR2213SC or AR2217 gets close to this and the Nosler data exceeds it with less powder. Some test loads need to be shot and chronographed so a likely max charge can be calculated and worked up to. More in due course.
Regards Grandpamac.
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