filling butane cylinder

Odds are you can use propane instead of butane, Very slight difference in the amount of heat produced, major difference is the vapor temp, Where as butane is not much use when the temps drop below freezing, Propane is good to about minus forty.. But in this country, it is not uncommon for greedy dealers to sell butane as propane in the south, less you get real cold, you will never know the difference.. Should work both ways. (Butane is less expensive you see so the dealer pockets the extra profit when he sells Butane at propane prices).