This requires fastman's limit adjuster (i have added it but may require more files) and CLEO and is built off of Bako19DZ's new weapons added mod on gta forums
this mod uses models taken from other mod creators such as slingshot753's models, KiloRyu and many more creators
and other rockstar games such as manhunt.
there are also many models in these files that aren't currently used so you could use them as a alt model
Each Ammu-Nation interior has different stock and unlocks and certain points in the game, although not all of the guns have been added most of them are
You can press O and K and the same time to bring up the weapon spawner which then requires you to type in the weapon name

this is still a work in progress so make sure to send me any feedback or support