Unlock infinite ammo without playing online

I suppose it depends on what you consider to be "100%" in the game.

Getting all of the achievements is what is required for the Xbox Dashboard to put a game in your "completed" list. If you're going by achievements, there is no achievement that requires you to get every medal (Seriously 3.0 specifically does not include this medal), and no specific achievement for this medal.

Rules:

• You cannot get the ribbon while playing alone. There must be other people playing with you. Plugging in a second controller might help, haven't tried it.

• You can only get the ribbon once per spawn or once you fail a wave. So, if you have gotten one ribbon, there is no second ribbon in the same life. So , if you are only after the ribbon, just die, or restart manually after getting the ribbon, repeat until 100, which will give you the Infinite Ammo Mutator.

• Which map you play does not matter.