Might be worth reading up on some of the differences here:
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Generally... all the Target Action rifles are large shank. Pretty much any long action (with the exception of the 110BA) should be small shank. *Most* short actions are small shank... but that can bite you too.
The barrel nut on a large shank is noticeably shorter than on a small shank. Other than that... get out your calipers. Small shank barrels are closer to 1.060, large shank closer to 1.130"