Gun Freak wrote:Duh

Remember I've never made a hybrid
The correct answer is "I haven't made a hybrid yet"
Gun Freak wrote:What keeps the stem from falling out when there is no pressure in the cartridge? I see how it would be easy to put it back in but it would be a pain to do all the time.
Nothing, and yes it's a huge pain in the arse.
LeMaudit, I modified your design slightly. The aluminium insert gives all round spark gap potential and also reinforces the synthetic bit to make it less likely to blow out on ignition.
What I don't like about this is that the rear seal cannot be serviced.