Carpediem,

to a degree you can get used to most LOPs that are not too far off for comfort. I started shooting shotguns with an off-the-shelf Beretta a long time ago. When I had a gun professionally fitted to me at H&H I felt most comfortable with a stock design that turned out to be an exact copy of my original Beretta. So if you have a shotgun or double rifle that you shoot well with already, simply use it as blueprint for other guns.