The Bundeswehr investigated the claims that the H&K G36 was suffering from accuracy problems and found that the rifle was not at fault. The problem lay with one of their ammunition manufacturers who were supplying ammunition with copper jackets that were to thin. AllShooter.de has published an article and a statement issued by the Bundeswehr (auto-translated with Google) …
However, this was clearly refuted by extensive research by an independent expert, the Ernst-Mach-Institute of the Fraunhofer Society. Cause are rather individual munitions (lots) of a manufacturer. The in the Bundeswehr used for the G36 ammunition of caliber 5.56 mm x 45 DM11 is procured from different manufacturers. In the manufacture of the ammunition of the bullet jacket is plated. Through various manufacturing processes the manufacturer resulted in some cases a different tin thickness of the shell casing.
This tin thickness has an influence on the bullet trajectory in hot geschossener weapon and declared the meeting changed behavior. Nevertheless, even this ammunition is fully safe to handle. The rifle G36 is technically reliable and without flaws. It fully meets the requirements of current operations and the basic operation of the armed forces.
The DM11 is manufactured by MEN Metallwerk Elisenhuette GmbH. If you are shooting .223 Rem. or 5.56mm NATO rounds made by MEN, you would check the accuracy of it in case you also got a bad batch. I do not know if MEN sells ammunition locally to, or exports, for consumers.
Thanks to Felix for the tip.