Forearm comes off in hand when fired

[B. Dudley]

Sounds like your forend loop is messed up and the forend toggle is not engaging it enough.

[Chris Robenalt]

Take your forend apart and snap the forend iron back on the barrels by itself and see how snug the locking toggle is .
Chris

[J. A. EARLY]

Tough to do on a DH as everything depends on the wood separating the opening lever from the forend iron. The lever only takes the slightest pull on it to get the forend off. Trying to figure where the problem is; the lever?, the flat steel lever spring?, the toggle that engages the barrel lug?, the barrel lug?

The forend locks well on the barrels and lug. You can't pull it off. But when shot the recoil causes it to disengage.