Heckler & Koch USA has announced that it will be offering complete MR556 A4 upper-receiver kits, available with either an 11-inch or a 16-inch barrel. Customers now have the chance to buy one of HK’s complete top ends and install it over an existing lower receiver to make it easier and less expensive to upgrade.
Because the MR556 upper receiver uses a proprietary gas-operated, short-stroke piston system like the legendary HK 416 series, these new standalone upper receiver groups include their own bolt-carrier groups, gas-piston assemblies and adjustable gas regulators. There are quite a few nuances between HK’s tried-and-true short-stroke, gas-operated piston system and the traditional AR-15 pattern direct-gas-impingement action that can provide certain benefits for select shooters. This includes the ability to shoot 5.56 NATO ammunition with suppressors and through shorter barrels at the same time.
“We are proud to offer the A4 upper-receiver kits. Shooters can maximize performance of their current lower receiver without the need to purchase a whole additional rifle,” said Nathan Schueth, HK USA director of sales and business development. “For existing MR owners, the URKs can be used to upgrade their A1 with the adjustable gas block or have a second length upper to change kit quickly and easily.”
All new MR 556 A4 complete rifles or complete standalone upper receiver groups include upgraded and slimmer handguards in addition to barrels with a lighter profile and contour. These are easier to carry and handle and address some of the MR 556’s previous complaints.
Visit hk-usa.com to learn more about these new upper receivers or other products from Heckler & Koch.
