I've been wandering around the listings of double rifles of recent manufacture and have noticed something that has me a bit perplexed. Initially when the Sabatti rifles were starting to make their way into the market there was a great deal of derision about the vertical disperion on their test targets. Now I'm looking at some of the new Chapuis rifles and another I don't recall off the cuff and they demonstrate the same vertical ranging on their test targets as well.

My question is thus...Do they all regulate this "poorly", or is this vertically misalligned pattern a result of the method of retention during regulation? While I'm asking questions, (really, I could ask all day), how much effect does body mass and structure of the shooter play on offhand grouping of these rifles? I just took a physics class and they never should've taught a middle aged millwright stuff like that. I'm noodling force diagrams in my head and cannot for the life of me figure out how a single rifle will shoot the same for any two people unless they're identical twins.