I started recently to top fuse my canister shells because sometimes, rarely though, a flower pot is happening. Also for heavy shells it is mandatory to top fuse them. What i have noticed is that sometimes my spolette do not light up. I i am using 2 pieces of blackmach fuse at the top of the spolette for easier ignition. When i bottom fuse them i did never had that issue, they always got lit. Any idea how to solve this problem ?