After finishing an interview with Stan Russell I took a video of the later style dual 12 gram co2 adapter, which was developed by Mac 1 and used way before it’s integrating into paintball marker.
This piece attaches onto the end of a Sheridan / PMI rifle 12 gram rod that has been shortened and I believe pierces the 12 gram when it’s screwed in tight enough. When the pressure starts to drop you are able to unscrew the 12 gram screw and the remaining pressure vents out the drilled vent hole.
Mac 1 added this adapter in modified Long barrel K rifle, K1, Mac 1 Mojo, Pump Twist Dual and some Stan Russell creations such as this hard chromed Annihilator / Marauder rifle (as it’s seen on in the video).
Find the pictured rifle in an article at:
Another article on the Pump Twist Dual can be found at: