Alright, I stink at MSPaint, so here it goes: LouisXIV's famous semi-automatic "gun" (https://www.instructables.com/id/Knex_Powerful_Semi_Automatic_Gun_1/) has a lot to do with this. I was thinking how to make a semi-automatic gun when this idea popped into my head: You have a bunch of grey connectors in the barrel at a time, but either a gap just barely too small for them at the end, or LousXIV's mechanism, is at the end, trapping the bullets in unless under pressure. There is a notched firing pin* that you pull back (see http://www.google.com/imgres?q=toy+smg&um;=1&hl;=en&sa;=N&rlz;=1C1CHNV_enUS370US370&biw;=1680&bih;=935&tbm;=isch&tbnid;=ijx0IyYxpqN_jM:&imgrefurl;=http://www.kapowwe.com/toy-mp5.html&docid;=dBcMAxK0eQoSqM&w;=573&h;=297&ei;=zSMzTtSuDY260AGU2bWMDA&zoom;=1 It is a toy that one of my friends used to have, you pull the orange tab back, and as long as you hold the trigger, the tab keeps going forward until you have to pull it back again). The trigger is a regular trigger, say, from TheDunkis' TDS, the difference being that the part in the barrel ends in a green rod to lock into the firing pin. There is tremendous pressure on the firing pin. When the trigger is pulled, the firing pin pushes and squeezes the grey connector(s) out of the barrel, but when the trigger is released, it locks into one of the notches on the firing pin. I am not sure about a detachable magazine yet, as they would all have to be lined up facing the end, but you could certainly load in a bunch at a time and see. *A firing pin with a concept used in conjunction with motors to make an automatic turret, you would have, for example, a grey rod, and lined on it are a grey connector, two blue spacers, grey connector, etc. **THIS GETS ITS POWER FROM THE PRESSURE ON THE FIRING PIN FROM THE RUBBER BANDS, THERE IS NO STRIKING MECHANISM. LIKE ALL CONCEPTS, IT WOULD PROBABLY BE WEAK, BUT CONCEPT GUNS ARE (ALMOST) NEVER MADE FOR POWER. Feedback is appreciated.