POTD: What Is This? Bullets For Ants? Posted November 21, 2016 in Ammunition, Photo Of The Day with 37 CommentsTags: H&K, Heckler & Koch, mp7 Dickson L. shared this photo of some MP7 rounds he got from his friend Joe. They are miniscule compared to the .50bmg rounds in the photo. They are 4.6x30mm. Advertisement