" farshot, If the single trigger double rifle is doubleing, then it is the fault of the rifle, not the opperator!"

Spot on.

I would strongly suggest he get the rifle looked at
by a gunsmith. Doubling rifles are dangerous. Someone may have played with and fucked it up.

Gryph - send me a PM on the other forum (I have just set you one) and we'll discuss it. Suggest a possible visit to Tim at McDonald's who has a few DR's on the shelf and a wealth of experience on all that are available on the market.