Weatherby Mk.V twist rate?

[McStern]

Dear all,

could you perhaps help me with this:

is it possible to identify the probable barrel twist rate from its serial number?
I own a 7 mm Wby, which just does not stabilize the bullets.

The serial number is H 240 8xx. It has been made in Japan. I was told the older barrels have 1:12, whereas the newer have 1:10.

Thanks a million

McStern

 

[barnesuser28]

you can check the twist rate with a cleaning rod