If you do enough shotguns shell reloading, you will realize that load recipes only applies to the results with the publisher's components, their shotgun, etc. Those loads were safe in their guns. Now, you try that exact load in your gun, and you may see pressure signs on the case hull, loose primer pocket, or a stuck hull in the chamber.
There are huge difference is bore dia of shotguns. Also, some have smoother bores than others, some have the forcing cones extended, and on and on. Powder and primers vary from lot to lot. Crimp has a tremendous impact on pressure. So, you had better educate yourself on pressure signs and various influences on pressure.
If you are reloading shot shells, and you read where a load is running 11,000 cup, you may had better back off and work up to it.
Examine wads on all shells tested, look at the general condition of the wad. If the gas seal is blown, this indicates high pressure and the load will not pattern well. I have through for a long time thought that lubed wads would make for better patterns. I spoke to Dave Fackler(founder of Ballistic's Products) about this a long time ago and he suggested dipping the wads in Motor mica to help the wad transition through the choke. According to the Machinist's Manual, the coefficient of friction is greater of plastic on steel vs steel on steel. So, reducing friction of the wad against the barrel may pay HUGE dividends in terms of reducing pressure and better patterns. I have wanted to rub Imperial Sizing Wax on the outside of some wads to test, but never have got around to it due to multiple shoulder surgeries.
