They fit pretty tight. A shot of a penetrating lube around the perimeter of the plate, with a few minutes of soak time, will sometimes help. I have, on occasion, removed the barrels, slid the breechblock into the closed position, and pulled the triggers to unleash the percutators into the plate. This is a last resort type action.
Remember to have a rag placed in front of the breechblock, for containment, if you try the last resort.
This might be a good time to mention that, unless it's broken, there is no reason to dismantle a Darne breechblock. Just a thought.
Best,
Ted
