I’ve run across a storage bin of powder that is probably 25-30 years old. It was stored in a dry garage, and temperature swings would have been from occasionally about 30°F in the winter (but more often 35°F to 40°F) to about 80°F in the summer. There are many powders that I don’t use in this lot, but the ones that I’m most interested in are Norma MRP and Reloder 22. The MRP metal cans are unopened with the metal seal still in the lid. So my question is: Will this powder be usable now, after 25-30 years (or possibly 35 years) of storage? Can I assume that it will have the same burn characteristics and energy output as newly-obtained MRP? Will it be completely safe if loaded to the usual MRP levels?
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