@Shaydee I do not have photographic / video evidence if that is what you're asking.
From a lot of field testing at 80-100M (real) in ideal conditions collectively we confirmed the differences between the two barrel lengths - STD & G spec.
Theres a lot of false info on forums for sure, and anyone can take ot leave anything 😉
Agree with @Skara and @Shaydee on both sides yes the law is set on Joules, but conversely as stated most stock guns will be above the limit as soon as you run anymore than 0.2 due to massive factory over volume.
Most snipers are the most honourable of all airsoft players, they appreciate distance, the power they have, but moreover they enjoy the sport for the satisfaction of a long stealthy hit.
This is only achievable with joules.
If everyone was Joule legal then sniper rifles / 500 FPS should be banned cos who the fuck fires 0.2 from a sniper rifle!? 😂
It should be 450 FPS limit.
@leadly please just get a std style inner barrel, get a Prommy 6.03 or other equivalent.
As you say the stock cylinder can provide a whole lot of air and there are many ways to reduce this.
Getting volume right will allow the BB to gather energy, leave the barrel cleanly without turbulence, and make the shot report quieter.
You have the best tool already - a chrono.
Time, effort and patience will reap maximum joy in game, provided you don't have the shakes! 🤣