Lagopus, I will say the Uk proof houses are strict, I had a custom made 6.5 x54 mannlicher made for me in the States over the last 2 years which I got a few weeks ago, for details see link below

http://www.chuckhawks.com/m-s_custom_rifle_hays.htm

However I got Hollands to check it for me before sending it for proof. The proof house will not accept for the reasons below,

Bolt will not go over the Go Gauge
Bore dia. 6.54mm, oversize by 0.06mm
Groove dia. 0.263" undersize by 0.003"

Now I´m not bothered, I don´t intend to sell it and it shoots 3 shot groups of 5/8" at 100 yds so I´m happy, I think there must be differences in bore and groove sizes in some countries compared to others (this rifle has a new barrel !) best, Mike