Don't know Stan, but bp is not hygroscopic. I, and others have tested that quite thoroughly, and it is well documented in the literature as well. That is why loads that are 200 yrs old will detonate just fine.

FWIW, I routinely wipe all the oil from my flintlock and load it on or about 19 December, carry it all over central Iowa, and unload it w/o firing on the evening of Jan 10 and never find a spec of rust.

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BrentD, (Professor - just for Stan)
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