I'm glad I rethought everything and came up with another concept based on my old bullet designs. I did some simple tests, refined the locking mechanic to work for greater rubber band forces and whatever not. Now it's some kind of hammer working like a bullet with a hopefully gear-powered primer (like I used them before). It trigger a bullet with ease, You can pull with a handle... Everything worked fine so far! And the best is that it is very small, as long and wide as a normal bullet.
Though everything is fine, I'm a bit pissed off today. Meeeh, it's turning summer here and I hate it soooo much to not be able to wear a jacket while "traveling" from A to B. Cities stink so much, you'll regret running around without anything to prevent surrounding smell filling every single pore of your body. However, I have 3/4 days in a week I need to go somewhere, so it's definitely not as bad as always going out for a longer time.
Bah, summer. I like the sun, but I don't like how warm it always gets then.