Weapon help

So I was using the smg upper and lower up until chapter 4. Then I take it apart put a shotgun on 2 handed frame on the upper put the military on the bottom and it is only 1 shot now no rapid fire. Really wanted the shotgun smg combo. Am I missing something? Anyone make one?

<p>Check which tips you are using.</p>

That's what was missing. I can see how to craft them now. But where did the smg tips go when I broke the gun down?

The SMG tips will be in your tip inventory where they were when you built the gun the first time.