Quite a lot of dead-space, but it'd work just fine, as long as the spring....Well they're all pretty much the same idea really, just variations on a blow-forward design, so a lot comes down to ease of building I guess.
Of course that's the key bit and why I posted here, having an idea is one thing, building it is another entirely, so ways to productionise the ideas are what I was after.
reading the topics and so on, but i kinda lost interest in spudguns three weeks ago, builing the high voltage ignition for my hybrid when i got shocked and nearly killed myself.