Not looked into it,but heard this lot carry air rifles,best get confirmation first.
http://www.awexpress.com/
Thair must be loads of rifles being posted every week,only a few are being sent to Ireland....so its a bit of a lottey.
I am the guy whos R10 is in Belfast,so unless your sending it to Scotland,where the risk seems to be greater,you should be fine.As a precaution,i would mark for road travel only on the box,and empty the buddy bottle completely.