Originally Posted by max344
Would one have any advantages over the other ?
direct mount .vs. rings & base
Rings & Base are 3 separate pieces that need to come together and form a union, and if any one of these pieces is machined out of alignment, you won't have a centered, on-same-plane alignment, which will torque, bend, or damage the Scope and keep it from being over the "Center-Bore" of Rifle.
The Rings and Bases of Today are machined, or CNC'd much better than their older counterparts, but you still have the possibility of a Scope being damaged if not watching carefully with installation.
Now, with 1-piece Ring/Base Combination, you have a machined(actually CNC'd) piece of metal that is cut in a precise way that everything is center-bored to within around .001"-.005" of each other. This gives you BETTER than what any separate Base and Rings will give you, which is why 1-piece Mounts cost twice to 4 times more for good to very good Scope Mount systems.
Go with Leupold, Warne, Dead Nutz, Burris and other top mount systems and don't look back. These Mounts will run around $200 to $500. And using a US Optic Scope, you'll want quality.
Use Blue Loktite for the Base Screws(only) and Torque down to recommended and you will have a very stable Mount. Also make sure the Base Screws are Steel and not some form of Aluminum by using Magnet to test, for the strongest Union to not break off over time. This will also not set up Galvanization of Corrosion of 2 different Metals.
I also like to run some Clear Nail Polish over the top of Base Screws and under the Mount Base, to keep out corrosion from getting into Joint if this is a permanent situation.