My M70 HV in .223 is based on a regular short action spacing, but the scope base is from a WSSM model spacing. The mag box has a spacer in the back to accommodate the shorter round and bolt travel. Similar to the older long actions chambered in short action calibers.
Measure your bolt spacing and see if it matches up with either of the three listed at the bottom of this page:
http://www.midwestgunworks.com/page/mgwi/ctgy/winchester-model-70-information
