Yes I too would like to know if there are any issues the N-SSA has with Hern mortar barrels? What 's the point in getting a barrel if it can't be shot at N-SSA events?
The answer to this question is a simple one. Many people do not shoot at NSSA events.
Personally I have never been to an NSSA event., let alone shot at one. And I am sure never will. I do however have 6 cannons and will be having 4 more soon., from someone on this board., for a grand total of 10 Cannons. None of which have been NSSA inspected or ever will be. My cannons are something I have built for my needs to my specs.
It just really dependson what YOU want to do with this Mortar, If its NSSA then you'll have to follow thier rules.
The real answer is :
Owning a cannon and shooting it .,displaying them., and instaling them on your ship is simply "Pure Pleasure".