I did a previous test with Speer .38 spl +P 135 gr Gold Dot from my S&W 638 and it had less than stellar results. This load is supposed to be one of the few recommended loads for a short barreled .38 revolver and it did not perform as expected. I thought it might have something to do with the colder temperatures the day we did the testing so I redid the test. I left the revolver and ammo in the refrigerator overnight and kept it in the cooler on the way out, then fired a couple shots with it cold and one with it warm. I also fired a shot from a 4" GP-100. All shots were through four layers of denim and impact velocities are noted.