With the MP5, springs become the argument for the first time. Every metal spring you put into one is a spring an AK also wanted, and the rifle wants more of them. A group that just raised its Level 3 workbench with one rifle body and one SMG body in the box has to decide which gun gets the springs first.
Level 3 also changes where springs come from. Learn the spring blueprint next to the MP5 and they stop being loot: each costs scrap and HQM at the same bench, and that is most of the extra scrap in the calculator's full view. The rest is the SMG body unfolded into scrap, and the body stays loot either way.
Tip
A broken MP5 is worth recycling. The ordinary recycler always gives one spring back, and the body half the time.
Short on springs? A Thompson uses one and keeps fighting until the box refills.
Questions
MP5A4 ×10: how many resources?
High Quality Metal ×150, Metal Spring ×20, SMG Body ×10.