Better re-check your input data. Using their configurator as follows...

Make = Savage
Model = 12 Top Bolt Release
Choose Action = Short Action, Center Feed, Blind Magazine, Bull Barrel

...I got 5 options, At-one, At-one Thumbhole, Pro Varmint, Spike Camp, and Varmint Thumbhole, all which have the exact same barrel channels listed at the bottom of the page:

Barrel Dimensions: Point A = 1 5/16" and Point B = 1 1/16" Center to Center of Action Screws: 4 7/16" Over All Length of Part: 31 1/2" Comes with Boyds' 1/2" Rubber Recoil Pad. It is your responsibility to confirm the dimensions of your firearm with the supplied dimensions of our part. ATTENTION CUSTOMERS: New action screws are needed if your action screws are shorter than 1 1/4 and 1 1/2 respectively. These are sold separately on our Accessories page. This stock is designed for the Savage Blind Magazine with Center Feed Action and a top bolt release. When you disassemble your action the magazine box will stay inside the stock when the barreled action is removed. If the magazine box stays attached to the action, you may need the Staggered Feed Model or STAGGERED FEED version we offer. Due to the many variations of trigger guards that have been used for Savage Actions. Boyds uses a flat bottom metal design. Fitting for plastic and some metal models may be needed or contact Savage or Brownells for the flat bottom design. All finished parts have been CNC inlet to Boyds' House Action. Variations may exist from firearm to firearm, minor fitting may be required to get that perfect fit to your firearm. Natural cosmetic imperfections such as minor knots, burls, heartwood, mineral lines or minor cosmetic fill work are not considered a defect and will be subject to the 12% restocking fee .
If you'd used their stock configurator for the rifle you actually have, not a bunch you don't have, you would already know why the Heritage is not an option see the graphic here.