some observations with my 19b. I've had the sparking button and hot button. I think the way the spring floats in there (not a good fit) it jams somehow at an angle and maybe takes the button with it to an odd position to make the spark? Yesterday i tried to use the locking ring to lock it and when loosened it must have taken the button up rather than down, because it was autofiring when it should have been locked. Sorry i'm not a modder and don't understand the internal action of the button, so it's hard to explain lol.
that derin screw washer that holds the pin. Can it be left screwed out a hair to raise the action of the brass post? seems it would make a better connection with the battery that way. Personally, sparks and hot buttons scare the crap out of me, so i'm hesitant to do too much away from stock. I do have an O-ring on the brass/magnet post to shorten the throw.
While putting the O-ring on the post, I noticed a little gray tab on one side below the top where the magnet is. Is that supposed to be there? Could that be the sparking? It looks like the tab is an extension of the magnet (same color) where they press fit it in. For those wanting to remove their magnet, it could be helpful to heat up that tab to pop it out? I can take a picture if you guys don't have that tab.