LOP for a big-bore double

The one and only time I've had a double rifle built just for me, I had to take several measurements to ensure the fit was "custom". Based on my submitted measurements, a LOP of 14-1/2" was deemed appropriate by the manufacturer. I later purchased a cheaper double in a smaller caliber for practice. This one had a 15" LOP and actually fits me considerably better than the 14-1/2" LOP. Does anyone on here happen to have a good means of estimating the appropriate LOP for a big-bore double based on measurements?

Instead of estimating, I went to Cabelas and tried a shotgun that could be adjusted to the user's comfort. I measured it at 15.25". I sent the rifle off to my rifle maker and he said that for a dangerous game rifle you probably want about a quarter of an inch shorter. (for quick mounting). He made the L.O.P on my .470 at 15" and it is a joy to shoot.

I have only ever trusted mounting an adjustable gun up onto my shoulder or mounting every last rifle/shotgun in the cabinet or safe and seeing how they feel and what my sight picture is.

Maybe someone has a better method for you.


A few failures from trying to just use the numbers in the past:

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