Yeah, that is about right for a full canister, both the 4oz and 8oz. (100g is slightly less than 4oz and 230 is slightly more than 8oz.) I figure about 100% for canister weights vs gas weights for the smaller canisters. Larger canisters are more efficient but still weigh about 2/3 of the fuel weight.
I got 3.6-4.2oz amungst various manufacturors about 7 years ago.
I got 5.8 and 7.2oz between two different larger canisters 7 years ago.
They vary, even amung the same manufaturor. Fuel, metal thickness, rolling, sealing, valves, etc. Nowdays, they have dropped the ounce usage in favour of the metric weights. Coleman canisters were always the heaviest, as I remember.
You ALWAYS need to add the canister for the true fuel weights.
This is why I say that alcohol and canisters are about equivalent.
Ethanaol/Methanol blende is about 11000BTU/lb, but it only takes a 1oz bottle to carry up to 16floz.
A canister starts at about 22000BTU/lb but adding in 100% for the can, this drops it to about 11000BTU/lb. I usually figure about 13000BTU becuase it isn't quite 100% fuel/can and it is more efficient with the on/off&simmer valve.
For comparison, WG is around 17000BTU after adding in for the container. Kero is slightly higher. Hexamine or Esbit was about 12000-13000BTU(soot may drop this slightly.)