Quick Guide to crafting weapons

• Build MK II until you get the mods you want.
  
  • [Pen] can only be build (Rarity upgraded can get you: [Dmg] [Acc] [CrtD] [CrtH)]
    You need build [Dmg]x2 [Pen] to get [Dmg]x3 [Pen]
    
  • Mods are random you'll get good mods for every 100-500 build
• Apply [Superior Experimental Tech Upgrade] to the weapon.
  
  • You should get to MK VII-VIII with one experimental upgrade
    
  • If you don't get the rarity upgrade with one experimental upgrade, Do not try to upgrade the weapon further (It's too expensive and the rarity chance is too low)
    
  • Do check if it's worth selling on the exchange
• If you get a rarity upgrade with the mod you want from MK II to MK VII-VIII (Ex. [Dmg]x3 [Pen])
  continue to upgrade it to tier MK XIV

That is it. If anyone have any suggestions to improve the guide, let me know in the comments...