I have been using French actions for doubles, it seems that the French used to double and tripple proof their guns as a sales point and thus they are rather over built as far as strength goes. Cheep guns are just that, cheep. This usually means low strength and such guns as the 311 and 5100 should be left alone. Another point about these guns is that with the amount of work involved in building a double rifle why start with a club? To me it is like putting lip stick on a pig. It looks a bit nicer but is still a pig

Any action you use should have double underlugs and double bites, also a third fastener is nice along with side clips. Check the proof marks and you should be able to determine if the pressures of the chartridge fall within this range. In all cases you MUST reproof or have the gun reproofed! Your life and saftey depend on it! My addvice is stay away from "cheep" gun (low quality like the 311) However you can get some good buys on very good and strong guns if you shop around. Keep in mind that you are building the gun so finish does not matter to you. Worn blueing, dark stock and such drop the price as will pitted barrels.