Royal Mail will carry airguns via Tracked 48. I described the last one I sent as a "tack driver", but you may be better off being honest, as there is no issue with sending them using that service - they are listed in the terms and conditions for T48 on the RM website. No pressurised cylinders though (PCPs etc.), unless empty.


https://personal.help.royalmail.com/...detail/a_id/96