ok here's an update: just the tip was gotten by me after I received the MK II pack from collecting all the items in game required for the pack, then I built a weapon with a mk II Frame and both first and secondary tips as mk II weapon tips of my choice.
drill seargent must be done in a specific way. You must kill every mob without being touched, when they are all dead then shoot the drill. There's 3 rounds and the first 2 rounds need all mobs dead then the drill and the third round you can just hurry and shoot the drill.
ATM I am awaiting for an answer to why after I got all the achievements that I cant get the 50th achievement of completing all achievements (pc version doesn't work) the x-box version does not have this issue.
