280 Ackley

[JeffreyDeGraff]

Depending on the source you look at, there are big discrepancies in max loads for the 280 Ackley Improved. My rifle is a Smith Corona 1903A3 Springfield action with a 26” Douglas XX barrel. I’m looking for max loads, in my rifle, for Hornady 162gr BTSP. I’ve picked RL19, RL22, and IMR7828. I loaded one each of four different charge weights for each powder, going up in .5gr increments, so I can look for pressure signs. RL19 - 57.5gr, 58.0gr, 58.5gr, and 59.0gr. RL22 - 59.0gr, 59.5gr, 60.0gr, and 60.5gr. IMR7828 - 60.5gr, 61.0gr, 61.5gr, and 62.0gr (compressed). Bullets are seated .005” off of the lands.


JTD

[JeffreyDeGraff]

I got to the range today and fired 8 of my 12 rounds over the chronograph. Only 5 registered because the sun was setting and the light shining in from the side was messing with the sensors. These rounds are all with Hornady 162gr BTSP. Reloader 19 was first. 57.5gr - 2766fps. 58.0gr - 2790fps. 58.5gr - 2879fps. 59.0gr - 2921. There were no pressure signs with any of these. Next powder was Reloader 22. 59.0gr - error. 59.5gr - 2917. 60.0gr - error. 60.5gr - error. There were no pressure signs with RL22. Ive got IMR7828 left to go, then I will start testing loads.


JTD

[Jbotto]

Keep it up! I’m interested in your results. The .280AI barrel should be here within a month!


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[JeffreyDeGraff]

Hopefully I will make it to the range this weekend, and finish this little test up.


JTD

[JeffreyDeGraff]

Keep it up! I’m interested in your results. The .280AI barrel should be here within a month!


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Weather is too crappy this weekend to do any shooting. Hopefully next weekend.


JTD

[JeffreyDeGraff]

I finally got to finish my test. IMR 7828 was my last powder. 60.5gr 2992fps, no pressure. 61.0gr 3037fps, no pressure. 61.5gr 3063fps, primer started to flatten. 62.0gr 3077fps, primer flattened and had slight cratering. I think that I will start my load development with IMR7828 and use 61.0gr as my max charge. I will start a new thread when I start my load development.


JTD