Thanks for your feedback, I really appreciate that! It takes insane amount of time to shoot and edit these short clips and in same cases/scenes we need to rent some cinema equipment and they're not cheap.
This particular build is not mine, so I don't know all the details, but the gun has 350mm unchoked 9mm barrel, HuMa tuning regulator which is maxed out at 150bar. From 250bar fill you get around 4-5 good shots at 700fps with 81gr JSB's. With NSA 75g HP's which we used in the film, the muzzle velocity is slightly lower.
The valve does not need any work, the most restrictive part is the plenum size, which is obviously too small for this caliber. But again, bigger plenum equals less reservoir volume and lower shot count, so I think this is decent balance between shot count and power. The moderator must be of course modified to allow bigger projectiles go through and same goes to the end cap/ring of the moderator as it could otherwise touch the bullet.
It handles actually very well, some recoil but not bad considering the power/weight ratio!
Again, thanks for your comments!