Hi guys. Happy New Year. I recently finished to read Dvoryaninovs tetralogy on small arms munitions. Soviets tried to develop exposed steel penetrator 5.45 bullet, they tried at least 3 different bullet constructions but ultimately failed, because of steel tip cannelure, which created to much drag, and a brass jacket which deformated in a barrel. But the results were still very promising, as Dvoryaninov writes that bullet with exposed steel tip is the most preferable solution to boost bullets penetrating power. By that book 5.45 with exposed tip bullet had at least 25 or 30 % advantage over 7n22. And my question to anyone who read ABC of ballistics, how americans solved problems with EPR ammo, if they they had some?