Tom, do you mean that tiny powder grains could work their way into the open flash hole & could cause weird things?...wonder if you could , with a tiny artists brush, put a film of varnish across the open flash hole?
But then again that could also cause weird shit to happen....
Jose, ...I guess you gotta have to put a couple in the chambers n do the stringbehind the barn test
Good luck...where there's a will, there's a way...as was proved last night...yeah!
Let us know what happens when you pull the string man
cheers
Franc