I love it did you plug the pump or anything else, Those single barrel ranges seem a bit low. Reloading must be horrible. You better make sure it lasts the whole round of defend the core or else you are in trouble.
You could do similar to the gemini and link them with polycarb or even wire. You could cut off the existing handles and just use wire so push up the catch plates or even put a delay on one. With this the trigger would work like a doubleshot. It could take exsesive amounts of maching parts though. Make a writeup when you figure it out.
Thanks for all of the feedback. I changed foams so I didnt want to use petg again because the darts are way loose. I will just save up for brass then and do it the clean way rather than do all that messy work. If I use 17/32 with 18/32 to act as a coupling will the 17/32 fall out when tilted down or stay in the 18/32 brass.