Here is a subsonic round I picked up in the early 90’s either at Grendel or Knights Armement.
If I remember well it was designed to be shot in a modified M16.
It was given to me as a 300 Whisper and I put it in my drawers and forgot it.
Right now, sorting my rounds, I check it again and I realize it doen’t fit with a 300 Whisper.
I had a loose bullet but I don’t know where it is.
The bullet was heavy and very long.
What is it ?