In theory, an bullet made entirely out of "copper alloy" could potentially provide superior barrier performance, especially against windshields. An average windshield is quite a formidible barrier for M193 and M855 bullets. The windshield seperates the core from the jacket reducing mass and lethality of the round. There are alot of variables when shooting at windshields, such as angle of impact and distance, but generally, a solitary shot with M855 will be sufficiently destroyed to an extent that its unlikely to have enough retained mass to be sufficiently lethal, though glass and copper fragments could cause injury. A windshield must be weakend to a point where intact bullets can pass with minimal to no damage and maximum retained weight. Bonded bullets have the core
and jacket bonded together making them much more resistant to seperation increasing retained mass. Federal Trophy Bonded Bear Claws are an excellent example of a bonded rifle bullet which is effective against windshields and is readily availible without PD letterhead. So long as the bonding process is effective at eliminating or impeding core seperation, any decent bonded bullet should provide sufficient performance superior to standard ball ammo. People are generally skeptical, especially around here, when it comes to new ammo making boastful claims which havent been independantly varified. IIRC, 100% copper bullets are illegal, so I am not sure exactly what these bullets are made of....but in theory, a solid 1 piece bullet that lacks a jacket/core could perform as well as TBBC or better. Its promising, and perhaps worth a further
look as I prefer jacket/core to be seperated during the manufacturing process rather than when I am trying to stop a rushing vehicle. I too am a "wonder bullet" skeptic, but provided the reasearch is there and it doesn' constitute illegal AP ammo, it could be worth a serious look. That being said, I am in no hurry to replace my patrol bandoleer of D&H magazines loaded with TBBC's with HSM's new barrier ammo. I would howver, be curious to see further testing results.