^^ AR15, pushups and chinups are great for building upper arms. I picked up a piece of conduit yeasterday to make a chinup bar. If you have a couple pieces of heavy furniture close together, you can also do dips. For forearms, try doing pushups on your fingertips. Or get one of those squeeze thingys. There's also isometric exercise. Try pressing your hands flat together in front of your chest and try pushing both ways. Also clasp your fingers and try to pull them apart. This helps your chest and back as well. There's all kinds of stuff like that you can do.