Somewhat strangely, there were two different military .38 Special rounds designated as the M41. The first one used a 130 grain FMJ bullet and was loaded to a pressure of 13,000 psi. It was intended primarily for use in USAF flight crew revolvers having alloy frames and cylinders. While the MV was given as 750 ft/sec, just how that was measured was not specified. Those alloy revolvers were withdrawn from USAF service early in the 1960s, and thereafter the M41 round was uploaded to 16,000 psi using the same 130 grain FMJ bullet. The MV of the higher pressure M41 is given as 950 ft/sec, but again, the conditions under which that MV measurement was made are unspecified. As I earlier stated, my personal muzzle velocity measurement of the low pressure M41 round in two different 6” barreled revolvers gave an average MV of slightly more than 800 ft/sec with a SD of about 25 ft/sec.