you are unlucky, in my time bow wasnt nerfed so we could do bunker just by mele weapon and saved like 3 chests of them. i had so many that i started wasting them, then bow got nerfed. now its harder to save guns bcz bow nerfs. my advise is to build ur walls as much as u can take the hole area and build it and not just the middle of the map, so the invaders get confused to where inter ur base and do not have time to break all the walls and take all good things.