I'm sure a Weatherby dealer could get one for you as they are on the manufacturers website.
Product Line PA-459, Threat Response
Choke Extended, Ported Cylinder
Stock Synthetic
Sights Fiber Optic Front, Ghost Ring Rear
Gauge
12 18 1/2" 3" 5+1 39" 13 1/2" 6 1/2 lbs.
20 18 1/2" 3" 5+1 39" 13 1/2" 5 3/4 lbs.