Whatever the price of the gun from a £50 baikal to a £50K London gun, I have seen issues with all of them - it all depends on how close you look.
I admit, I am a picky person as well, and a gun has to be right otherwise I fret!!! However, you have to learn to live with some things. Anything that has an element of hand-finishing or handbuilt ALL have "issues" if you look close enough.
Some of the Japanese built Brownings (AKA Miroku)are finished to an unbelievable standard internally, with virtually no tool marks at all. I have seen Purdey's and Hollands internally with significant file marks...
and some of the top tier engraving on some recent guns IMHO leaves a lot to be desired - pheasants looking like parrots etc - don't get me wrong I am a great fan of the old naieve art style engraving and favour that over some modern engraving, but there are limits.
and as for single triggers on best London guns - forget it, nearly every one I have seen - new and old has had problems, and even led to new guns being rejected by new purchasers !
Jonty
