I have read in the past & it was written by a "Qualified" Ballistician. There are numerous factors which all play an important role in determining pressures in a Rifle & all must be considered. In a shotgun, the pressure is built into the shell with few outside factors of much consequence.
The few caveats worth mentioning are;
1st As already stated the built-in pressure should definitely be compatible with the gun intended to be used with said shells.
2nd, the above statement about the pressure being built into the shell assumes the crimp is free to open. Two things which can affect this are the "Loaded" shell enters the cone which restricts the opening of the crimp. This is a strog possibility if loading a roll crimp true 2 3/4" case in a 2˝" chamber. As already mentioned a stepped chamber rather than a cone is also a No-No. I have always relied on my own judgment rather than going to a "Qualified" Gunsmith but its hard for me to imagine anyone with enough knowledge to make a decision about using the longer hull who would not check out the cone. A quick glance into the breech will show that step as opposed to a cone.
