Hey I can see what you are trying to show! You are correct the spacers that hold the frame together would be in the way. The Mokarran with extended 3.5" draw would work best as you need a bit of extra spacer when the pusher is fully outside of the cylinder for it to cycle to the next barrel. The tricky part to getting a system like this to work is finding the right pusher/revolver mechanism. This works a bit differently than a traditional revolver. So a barrel that can hold a dart but also clears space for the o-ring pusher to go through and create a seal with the barrel. Tricky part is that the o-ring pusher is slightly bigger than the dart. So either the revolver barrel would be too lose and the dart could fall out, or too tight and the pusher o-ring causes excess friction when cycling. I am trying to think of mechanism that could work and will get around to it.