c11man wrote:thanks alot jimmy and tech.

73 shots seems a little low for how small my chamber is in my opion. but i could be wrong.

the number of shot will increase or decrease proporionaly with my chamber volume if i change it right?

Correct, except it's inversely proportional. Bigger chamber/less shots.

I haven't found any blatant errors in the math. As a double check I'll play with the numbers on volume alone using this from an earlier link above.

Liquid/gas equivalent (1.013 bar and 15 °C (59 °F)) : 311 vol/vol

A double check using the mole calculation and comparing it to the liquid to gas ratio will provide a fairly quick double check of the figures.

A 1Lb bottle of propane has the water capacity of 2.39 lbs of water.

1 lb of water is 27.680 cubic inches.

2.39 Pounds of water = 66.156 Cubic inches

66.156 Cubic inches of liquid propane = 20,574 cubic inches of vapor at standard pressure. Convert to your desired pressure to find the volume at the new pressure.