Aaron i'm taking my right as an American citizen to disagree. Just because it pressed your thumb off doesn't mean it can hold compression. could be pissing around the ring or gasket. Thats just an initial shock, that means nothing for holding any sort of compression. Granted you will always have leaks around the piston and such. I used to do that untill my lawnmower had a cracked jug and still Seemed to have compression. Once again N00bies 2 cents. To each their own though.