New to the group and somewhat new to the AR15. I have some questions on a build I would like to do. I am building a go bag. To keep in my vehicle and want to build an AR15. That I can put in my backpack. I have seen. Some foldable options And wanted to get some advice before I start building. The platform I'm wanting is this, as I'm wanting a carbine and not a pistol. I was thinking was a 15 inch upper as a 16 in upper is to big for my pack. The lower I'm wanting a collapsible stock. I also thought of a foldable lower. The reason why I'm wanting to build this is to keep in my go bag. My go bag I'm building is a plain gray backpack as I'm using gray man system to blend in case of a shtf or a break down somewhere. My pack will hold 3 days of supply's enough for me to get home. The area I'm wanting is something I can use for hunting if need be and for self defense. So I guess what would be a good upper and foldable lower.