Hi ive tested teral gas in my gun it works fine its a mixture of carbon dioxide nd argon not flamable
Teral is a mix of about 4% oxygen, 5% CO2 and most of the rest being Argon.
At 200bar in airgun the oxygen partial pressure is around 10bar, enough to oxidise oil so it could diesel on firing and if any of that Q20 penetrates back into the workings and then exposed to pressure it could still burn and generate heat even though the gas would not support combustion at atmospheric pressures.
You also get oxygen into the breech area each time you load a pellet so it almost certainly dieselling and the extra pellet velocity is not simply due to lubrication of the Q20. I'd be a bit nervous about doing this, could end badly for user and rifle.
Teral also has about the same ballpark physical properties as air in terms of speed of sound, viscosity and density so there is no advantage in using it to get higher muzzle velocities as you can with helium.
Helium, in theory safe, but really is it worth the expense just for the sake of a bit of velocity?
Seriously what is the bloody obsession with power?
Accept airguns for what they are, something that we can largely enjoy the ownership of without the hassles of licensing.
If you want high power (with accuracy) don't piss about with airguns, get a license and buy a firearm.
You may want to reassess. Argon gas has a higher molecular weight than nitrogen gas (N2 28g/mol, Ar240g/mol) and is more dense (N2 1.25g/L, Ar2 1.78g/L). As it displaces Oxygen and Nitrogen, it is used as a more "humane" way of culling chickens. Also meaning it is less compressable. Add to that, with the higher weight of Argon, it takes longer to navigate the turns in the path from the valve to the barrel.
End of the story; you get less of a volume increase at a slower rate on pressure release. Not only does that give a slower muzzle velocity, you also get less shots per fill. Seems a rather expensive way to get less performance.
Rather use compresed air, it's cheaper and works better.
At the very least please leave the Q20 out of the picture.....