The second-class and third-class FadeBurst Rounds invented by Zanthar Larkinson were rather weak.
It couldn't be helped. Their designs did not contain any special tech or materials that focused on increasing damage. When fired from a ballistic rifle, the rounds were more prone to shattering before it could expend all of its kinetic punch onto an obstacle.
Much of this had to do with the large proportion of hyper materials in the designs. They were decent at attracting E energy, but possessed disappointing physical properties. The greater the proportion of hyper materials, the weaker the overall construction.
This was a problem that plagued the Amaranto Mark III design as well. If not for Gloriana's excellent use of archetech and targeted amounts of high-grade exotic alloys to reinforce the mech frame, the ace mech would not have been able to spar so intensively against the Lamia Kailamassu.