Access to a chrono is a real bugbear for me, no gunshops (that I know of) in Powys, and as has been said - "rarer than rocking horse droppings".
I've been following the C625 saga and will buy one as soon as they become available, but untill that time I'm stuffed for chrono-ing my own gun, not that it has been tweaked as it was bought new - but I'm just not 100% as to what its poking out.

Ogri the trog