The Differences Between Savage Actions

Over the years there have been many changes to the design of Savage Actions. Below is a summary of the changes that have been made.

Savage Action Lengths

Long Action:  5.062" (all years)

1st Gen. Short Action:  4.522" (1959 - 1988)
2nd Gen Short Action:  4.275" (1998 - 2005)
3rd Gen Short Action:  4.400" (2006 - present)

Receiver

Pre-2003, Non Accu-Trigger has a flat rear scope base mount.

Post-2003, with Accu-Trigger has a round rear scope base mount.
Firing Pins    

The standard caliber firing pin measures .145" in the area it would pass through the cross pin.
On some (but not all) pre-2001 magnum actions the firing pins are .095" in the area it would pass through the cross pin.
The cross pin hole and the hole in the bolt face are different sizes for their corresponding firing pin sizes.
    
In 2001, Savage firing pin diameters were reduced on ALL models to the smaller size.

Bolt Faces 
   
WSM and UltraMag calibers use a controlled round feed bolt head instead of the standard bolt head.

  

Barrel Shanks

Standard barrel shank diameter on standard calibers are 1.055" x 20tpi. 
WSM, RUM, and SAUM calibers it is 1.120" x 20tpi. 

The barrel nut is also bigger internally, but has the same external diameter.

Some WSM and RUM rifles were initially made with the standard barrel shank diameter.

If unsure measure the diameter of the threads.

 
 
More details can be found on the Sharp Shooter Supply Website.