It is very important to understand that the load developed for an auto pistol should not be SHORTER than the Overall length in the manual, if one is given. The maximum load was developed for a specific OAL that should not be shorter than the load listed. I know it has already been stated, but it is a very important point.
Revolvers are not quite as sensitive as auto's, so long as minimum OAL is maintained. Pistol chamber and throat length varies by manufacturer in the same caliber, as it does with rifle chambers. What I do for autopistols is similar to the rifle OAL length technique and I measure the OAL at the point where the bullet ogive makes contact with the lands, if it can be loaded that long, and then shorten the OAL a minimum of .005" to a maximum of .010" making the loaded round specific to the chamber length of the pistol it is to be fired in. Naturally, you don't want it too long for the magazine and you don't want it any shorter than the loadmanual cartridge, or you will have to reduce the powder charge proportionately and the load manual will not tell you what that reduction should be. Make your reloads just like the one in the manual, or increase length to fit the chamber specifically, but make sure it still fits the magazine and has enough bullet shank in the case for adequate bullet "Pull".
