Reloading variations

10willd

Well-Known Member
I have been reloading for a few years now never had any problems always stuck to my manuals recipes but recently bought a new lee reloading manual and noticed both list RL-22 for my .243 which until now I have only used in my 300 WM but the Nosler manual says never exceed 42.5 grains but the lee manual says never exceed 45.5 grains how can there be such a big difference or if your a professional reloader is 3 grains of powder not going to create enough extra pressure to worry about
 

M275

Well-Known Member
Each manufacturer has it's own test barrels, plus it's own idea of what constitutes a safe load. They also apply a safety margin. A few years later they may re-test that calibre to add new bullets or powders, and the loads may be revised. A range of manuals will give a range of maximum loads. .243 Winchester seems particularly variable, with manuals suggesting loads with slower powders that don't burn cleanly or efficiently in my experience.

If you want a safe load then you can take the book maximum at face value. If you want to determine the maximum load for your particular rifle/bullet/powder/case combination then you'll need to try loads with small increasing increments until you start to see pressure signs like flattened or cratered primers, excessive stretch marks in the case body or extractor marks on the base. Once you get there, stop.
 

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