hum, I don't think it matters if the gas is 'ideal' or not. The manufacturer quoting 16g of CO2 in a 20cm^3 canister stored at room temperature. I'm confused as to where the 60 Bar quote comes from.
A manufacturer quotes a standard CO2 canister contains 16g of CO2 at a volume of 20cm^3.
So I need to calculate the pressure in the canister...
Using ideal gas law
P = nRT/V
n = 0.364mol (16 of co2)
R = 8.314 J/Kmol (universal gas constant)
T = 294k (gas is at room temp 21 deg C)
V = 20cm3...