Redemption wrote up a loooooong article with the history behind the weapons that inspired the creators of Red Dead Redemption when they were making the in-game weapons. Complete with comparisons between the in-game models and their real-life siblings, as well as a short history lesson behind each weapon.
Though it needs to be said that the Bolt-action rifle is inspired by a NORWEGIAN weapon, and not a Danish one.
"John Marston’s skill with a revolver may have kept him alive (or “above snakes,” as the saying went in the Wild West) for many years; but the following guns were fairly new on the scene at the time of Red Dead Redemption, and they offer Marston some exciting and deadly new tools in his arsenal to work with in his quest to tame the West..." - R*
Read the whole thing right here