This is an excellent - and long - article on the myths and facts of the AR15 in litigation.
https://reason.com/volokh/2023/02/27...m_medium=email
Retired Colonel Craig Tucker, U.S. Marine Corps, who served as an infantry officer for 25 years and commanded combat units in Iraq, wrote an expert report in support of Californa's case in federal court case Rupp v. Bonta. The Col's report states:
The AR-15 and M4 are both designed to fire a .223 round that tumbles upon hitting flesh and rips thru the human body. A single round is capable of severing the upper body from the lower body, or decapitation. The round is designed to kill, not wound, and both the AR-15 and M4 contain barrel rifling to make the round tumble upon impact and cause more severe injury. The combination of automatic rifle and .223 round is a very efficient killing system. The same can be said of the AR-15.
The remainder of the article describes litigation, the reason for such testimony, and the true facts of the AR. It is an excellent article.
I tried to review the case on PACER, but it is a huge case. Case no.: 8:17-cv-00746