I found lot of weapon components in large extraction settlements (higher security is better) but now I don't remember which BGS state it was. Sometimes it was 4 - 5 in one passage,
and usually in storage and power building. It was also very good for other tech - carbon fibre, titanium, tungsten carbide. In storage buildings they are usually laid on the crates, and it's true - not easy to see. Sometimes, after running through settlement I sit in SRV (if I have one there) and drive closer to buildings, and SRV radar shows materials what I missed.
Cmdr Frop, that's a good idea to share (ot trade) informations about especially good settlements - and players already doing it, but in private conversations.
Additionally, cmdr Frop, if you need Weapon Components just now, to engineer something, I can lend it to you (I have about 300) and because I don't need anything in exchange, you can simply repay it after some weeks when you have enough. Or maybe I'll need anything else. It's based on trust and long term cooperation, as cmdr SteveWW57 explained.