Many years ago, I purchased 1000rds of 38 Supers at the CMP at Camp Perry, Ohio! I figured they would be fine as they were loaded for the AMU! I fired a couple cylinders full in a 686 38 Super! TOO HOT! I pulled apart 20 rounds and measured the powder. The weights were from 9.3grs to 10.1grs! I looked in ALL my old reloading manuals and there was not one load of any powder that was anywhere near the much! I pulled apart every last round, saved the powder, and reloaded with the same powder but starting at about 6grs and worked up until I felt I had reached a save load. I loaded all the rounds I had pulled apart plus about 50 more I had setting around and was left with about a cup of powder! The left-over powder went up in smoke in the driveway!
To the OP! A recommended max bullet weight of 240grs is for all S&W N frame 44 mags. Prolonged use of heavier bullets will loosen up the gun!
jcelect