Using the Heckler & Koch’ MR556A1 rifle, chambered in the popular 223/5.56, as the platform to build a competitive rifle, and with input from many competitive shooters, the Heckler & Koch Competition Model was developed for both casual shooters and the most demanding competitor. Ideal for 3 gun matches, the Competition Model adds the most critical fundamental enhancements to the standard MR rifle. Foremost among these additions are the new 14-inch Modular Rail System (MRS). Lightweight and easy to customize, the MRS allows sections of accessory rails to be added by the shooter where desired, but keeping weight down and presenting a more ergonomic and comfortable handguard surface when compared to rectangular full rail systems.