I’m trying to understand the substantial difference in published load data for the 240 grain lead bullet. Modern Reloading second edition shows 20.6 gr @1510 FPS but Lyman‘s 49th has 20.6 @ 1258. I noticed Lyman‘s states the load is for handguns. Modern Reloading doesn’t state what test gun was used. Previously I worked up my loads and ended up at 19.1 gr in my S&W 629. I now have a second pistol in 44 magnum which is a LAR Mark IV Grizzly in semi auto. Looks like I’m going to have to develop a different load for it. Any ideas why these two manuals differ so significantly? I have not been able to Chrono my loads yet.