WD40 is not a very good rust preventive.
BOESHIELD T-9 did best in this salt water test:
http://www.accuratereloading.com/rustest.html
Might consider getting maritime firing pin spring cups for that environment.
ht tps://www.amazon.ca/Ghost-GHO-MSC-Maritime-Spring-Cups/dp/B008BD0NCI
BOESHIELD T-9 did best in this salt water test:
http://www.accuratereloading.com/rustest.html
Might consider getting maritime firing pin spring cups for that environment.
ht tps://www.amazon.ca/Ghost-GHO-MSC-Maritime-Spring-Cups/dp/B008BD0NCI