Does the Weatherby Vanguard Rifle share the same barrel thread as say, a Remington 700 ?

Believe they are the same as Howa, and they're metric.

26mm x 1.5mm, almost 17tpi, but not quite

The Howa/Vanguard has a metric thread 26mm in diameter with a 1.5mm pitch(approx 16.9TPI), the Remington is 1.0625in.(26.98mm)in diameter and 16TPI.