I know it was done and still is in old alloy colts and SW. My agent Colt factory book says check cyl. gap and action every 2000rds of +P. 38 standard PSI 17,000 and +P 20,000PSI. I have allways practiced standard 38swc 158gr. and carry the 158 gr. lswc-hp 158gr. I fire a few cly. full to check point of aim. I recall a article years ago by Skeeter that fired 2000rds of +P out of a M-37 with no effect on the cly.gap and timing. What is your feeling on the subject?