" not to put loads in plastic tubes. Static electrical sparks could ignite the powder,and several guys had the tubes go off in thier pockets."
I wonder about those reports concerning static electricity. Repeated experiments using static sparklers have not shown that BP can be ignited by static sparks.....there is just not enough heat.
See this link as an example - one of a few:
http://www.ctmuzzleloaders.com/ctml_experiments/sparks/sparks.html 
