Mixing HPA and CO2?

[Shrubbery]

Just out of curiosity, because I now own a Benjamin Discovery and it is advertised as being "dual fuel", meaning it can use both CO2 and HPA. What would happen, if anything, if I were plinking with CO2, and somehow ended up topping off from half-fill with HPA?

I'm guessing given that CO2 makes up a portion of atmosphere, I'd already be using a mix of CO2 in my HPA.

Are there any mixtures of seperate gasses that would be unsafe, between HPA, CO2, Nitrogen, and Helium?

[Roadworthy]

I don't have a Disco but understand it to essentially be a PCP gun.  They sell an adapter to allow it to use CO2.  I do not believe you can use both at the same time but if so there should be no ill effects mixing them.

[Tater]

Moved to the PCP/Co2 Gate.

[Back_Roads]

 Slower velocities will happen when the CO2 amount is greater than the air in the mix, best to shoot the CO2 out, or degas before switching, and vise versa, or velocities and POI will be different and not predictable.