Why is it so difficult from England. What is all this nonsense about end user certificates in Britain? For a sporting gun?? Have they lost their minds?
I have to agree with you and the logic of these tough restrictions can be a bit mystifying! However, it might help to understand that most of the developed world takes its responsibilities about international trade in firearms very seriously, France obviously is an exception.
Secondly, don't forget that there are international sanctions on riot control guns, often shotguns, and it certainly is not unheard of for someone to export these as 'sporting guns'.
As a matter of interest, have you ever tried to export a gun from the US? It may be little different. I would not be surprised if you have to produce an end user undertaking or similar.