I remember being told that propane bottles won't explode when shot, but one thing I have learned over my 54 years.......
Absolutely nothing is Sailor proof!
On the serious side, I get antsy just thinking about the possibilty of creating an unintended fuel-air-explosive mix. I work on petrochemical barges and have a healthy allergy to uncontrolled explosive vapors.
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This video is of a gas barge which exploded at an oil terminal in New York, killing two men. The vapors in an empty tank were ignited by an engine problem.
The wife and I have taken up plinking occasionally from the back porch with a cheap bb gun......a bag of fritos scoops provides a fair number of targets. We tied some string to some clothes pins and hung them in the trees....the squirrels love to clean up for us.....

(I do love living in the country!)
A Gun in the hands of a bad man is a dangerous thing. A gun in the hands of a good man is a danger only to the bad man - Charlton Heston
The only time a Texan has a pinky out is to see if the chamber is empty in the dark. - SFC M. Merino US Army