Powering 40mm grenades

[hawkafr]

What do people use to power their 40mm grenades  ie green gas or co2 was looking at a co2 charger filler bit at £60 is it worth it ? 

[THE FNG]

I've always used green gas and occasionally the nuprol black gas. Never had any issues. I've got a propane adaptor ready for the next time I use 40mm!

[Spartan09]

all my MOSCARTs (the ones that dont leak like a sieve) are all CO2 powered.

but word of warning...   dont try filling one with CO2 if your moscart isnt listed as being suitable for CO2 or if you are unsure of compatability.