As I understand it, the question of what is the diameter of the rings versus the diameter of the barb. If the barb is larger than the rings it will be stopped unless it exerts enough force to break the ring. Most likely the barb will penetrate until the taper of the barb is larger than the rings. This would possibly still allow several inches of barb to penetrate.
I would think the barb would break the rings, considering the pressure with which they appear to be ejected into their target.