… There's an article in HANDLOADER #119 on the Improved with data. The same article was re-printed in Wolfe's "Wildcat Cartridges" Volume 2 (perhaps still available). HANDLOADER has published at least two other articles on the standard and/or improved…
Be aware that various loading data in vintage
Handloader articles were not pressure tested and were simply the authors’ experiences. Use that data as no more than starting loads, they may - or may not - be above SAAMI maximum pressures for the cartridges. I know, I wrote for the Wolfe publications for years. Most data quality is probably no more reliable than what you find on the Internet today.
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