[Joe Sr.]

Also, IME, CO2 comes out pretty damn cold on it's own.  I believe it cools as it expands from liquid to gas, thus the freezing/frost that can sometimes form on a cylinder.  I may be wrong, as I am not a physicist...

True - except CO2 is never a liquid.

It's liquid in the cylinder due to the pressure. 

Google "paint ball fill station."  If you're filling canisters at home (I'm not, looks WAY to much of a risky PITA) then you need to either invert your larger canister or get one that has a dip tube so that you can transfer the liquid CO2.  Otherwise, you'll never get a good fill on a smaller canister.

People actually do this to save money.  Would scare the day lights out of me.

[Jimmy K]

Also, IME, CO2 comes out pretty damn cold on it's own.  I believe it cools as it expands from liquid to gas, thus the freezing/frost that can sometimes form on a cylinder.  I may be wrong, as I am not a physicist...

True - except CO2 is never a liquid.

Well that is true at Standard temp and pressure, as it sublimates.
CO2 is liquid at room temp and around 800 PSI.
http://en.wikipedia.org/wiki/Bottled_gas

Well what do ya know. (or what do I know)

[philm63]

Thanks for all of the clarification. I'm not too concerned about the temperature of the CO2, per se, I'm more concerned that the entire carbonating process works equally well from an equipment stance with the bottle at 70F or 40F which seems to be the case.

Oh, and interesting bit on finding the hot gas lines before drilling holes through them - good stuff!