Back when I was importing them, I was thankful that pictures of blown up Darnes were not seen on any of the boards.

They built rifles up to .500 Express on the R action. There are multiple locks, including a rising bite off the lever that engages an extension on the barrels, and a compound wedge held under extreme force, when the action is closed, by a serious action spring.

I'd put the R Darne up against any barn hinge gun for durability.
Best,
Ted