![Winchester Model 70 (.435) Pre 64 Long Action Magnum Alloy Light Weight Ring Base Combination (xxx704 series) - store.TalleyScopeRings.com](http://store.talleyscoperings.com/cdn/shop/products/alloy_mounts1_f932239b-95b0-4531-86c9-b719adb5a3fd_1024x1024.jpg?v=1456300587)
0.435 inches, refers to rear hole spacing for drilled and taped holes on top of the receiver.
For Pre-1964 manufactured rifles chambered in 300 H&H Magnum and 375 H&H Magnum
Winchester 70 Express Pre-1964 (.435 Rear Mount Hole Spacing for .458 Win., .416 Rem, .375 H&H, .300 Weatherby, and .300 H&H magnums)