The Leupold Backcountry Winchester Cross-Slot Base is designed and manufactured in the USA.
The Leupold Backcountry Winchester Cross-Slot Bases for Winchester Model 70 Long Action should work fine with that rifle.
Using Weaver rings on a Picattiny rail will work but the Weaver rings may be loose fitting. I recommend using Picatinny rings to mount a scope to the Leupold Backcountry Winchester Cross-Slot Bases.
Yes. The Leupold Backcountry Winchester Cross-Slot Basesare offered in either a 0 MOA or 20 MOA option. The 20 MOA option will provide more elevation adjustment when it comes to longer distances due to the cant of the rail.
The Leupold Backcountry Winchester Cross-Slot Bases that you can use for your Model 70 is MPN:171341 (20 MOA), or MPN:171340 (0 MOA).
You should be able to use the Short action Leupold Backcountry Winchester Cross-Slot Bases for your rifle. MPN:171341 (20 MOA), or MPN:171340 (0 MOA). I would still recommend reaching out to Leupold directly just to confirm fitment.
The Montana Rifle Company X2 should be able to use Winchester Model 70 scope bases. So you can use any of the Short Action Model 70 bases, MPN:171341 (20 MOA), or MPN:171340 (0 MOA).
Yes, they include the mounting hardware.
You will want to use either of the following:
Leupold 174689: Backcountry Cross-Slot Picatinny Rail, Winchester XPR, Long Action, 1 piece, 20-MOA, Matte
Leupold 174688: Backcountry Cross-Slot Picatinny Rail, Winchester XPR, Long Action, 1 piece, Matte
Here is more specific information for the models listed:
Leupold 174686: BackCountry Cross-Slot Picatinny Rail, Winchester XPR, Short Action, 1 piece, Matte
Leupold 174689: Backcountry Cross-Slot Picatinny Rail, Winchester XPR, Long Action, 1 piece, 20-MOA, Matte
Leupold 174687: Backcountry Cross-Slot Picatinny Rail, Winchester XPR, Short Action, 1 piece, 20-MOA, Matte
Leupold 171343: Backcountry Cross-Slot Picatinny Rail, Winchester 70, Long Action, 1 piece, 20-MOA, Matte
Leupold 171341: Backcountry Cross-Slot Picatinny Rail, Winchester 70, Short Action, 1 piece, 20-MOA, Matte
Leupold 171342: Backcountry Cross-Slot Picatinny Rail, Winchester 70, Long Action, 1 piece, Matte
Leupold 174688: Backcountry Cross-Slot Picatinny Rail, Winchester XPR, Long Action, 1 piece, Matte
Leupold 171340: Backcountry Cross-Slot Picatinny Rail, Winchester 70, Short Action, 1 piece, Matte