If you've learned to shoot classic American sxs, especially if your gun dates back before WWI, you've likely adjusted to a stock that is both shorter and has more drop than you find on classic British sxs. I once guided a hunter that showed up with a new Spanish gun, dimensions based on a professional fitting. He shot that gun on Iowa pheasants the first day and did not do well at all.
The next day, he switched to a Parker, which was the gun he'd been shooting prior to having the fitting and buying the bespoke Spanish gun. He shot very well. I tried mounting both guns. The Spanish gun was both longer and had less drop than the Parker. I told him that he had obviously adjusted to a gun that was "wrong" for him based on the fitting. And that he might very well adjust to the gun that was "right". But the difference between the two was significant enough that I doubted he'd ever shoot both of them equally well.
But your ideal dimensions can change based on how your body changes as you age. I'm thinking that's happened to me, because the gun I've been shooting best at skeet lately has an LOP of 14" and almost 3" of drop. Previously, 3" of drop usually left me looking at the top lever with even the front sight invisible. I'm sure my arms aren't any shorter (although I've probably lost an inch or so of height and definitely put on some weight.) But contemplating my next purchase, I'm thinking about guns with shorter LOP and more drop.
