In 2002 Savage began offering rifles in the Winchester Short Magnum (WSM) and Remington Ultra Magnum (RUM) calibers. When these were finally in the catalog, there was a change made to the barrel shank diameter. Standard barrel shank diameter on standard calibers are 1.055" x 20tpi. On the new WSM, RUM, and SAUM calibers the shank diameter is 1.120" x 20tpi. The barrel nut is also bigger in internal size, but is the same outer diameter and our barrel nut wrench will still fit. Savage also used this size of shank on the first version of the Model 10ML muzzleloader.
However, there were a few WSM and RUM rifles made on the standard barrel shank in the first production run. The best way to tell is to measure the barrel shank right against the nut. The larger barrel shank will have a step down approximately 1/8" ahead of the barrel nut. If your WSM or RUM rifle has a serial number with a "G" prefix, it is most probable it will have the larger shank.
NOTE: The Model 12 LRPV's, Target Series rifles and Target actions use the large shank size. Due to the extra heavy barrel contour used on these rifles there is no "step" in the barrel as shown in the picture above.
The quickest way to determine what size the barrel shank is on your rifle is to measure the length of your barrel nut. Standard shank nuts are 7/8" (0.875") in length, whereas large shank nuts are 5/8" (0.625") in length.
Information provided by Fred Moreo of Sharp Shooter Supply
vBulletin Message