Preset as in an option in storage to attach a particular scope and ammo type so that when you choose to put a weapon in your loadout it automatically adds the scope and ammo you chose for it.
Second, minus the Gandhare and certain others, every rifle available in the game is available in several calibers at any given time. We also have several rifles that are exact copies with different skins applied, which, now that we have customization, makes them even more irrelevant.
Huntsman .270, Stradivarious .270, and Warden .270 come to mind. Honestly, I almost never use either one. There's just so many better 4-8 rifles it's pointless to have it anymore. Which is a real shame, it's one of my favorite models in the whole game.
Now, .270 is a modified .30-06 shell case with a smaller bullet. That means the Huntsman could be a .30-06 and it wouldn't look any different. It could also be a .35 Whelen (a .30-06 case modified to hold a .35 caliber bullet) and still look absolutely no different.
.270 as a 4-8 is kinda meh, it works but basically any dlc will give you better options but as a 3-7 or 3-8 would be incredible because we have so few options for class 3
.30-06 is basically perfect as a 4-8, the sound of the Eckers is perfection too
.35W would be a flawless 5-9 option with great knockdown power
Plus, Hunting Simulator 2 includes this and it's not half as polished as Call of the Wild