I had a chance to shoot an H&K MR556 equipped with an OSS Inc suppressor about a year ago. The guys at OSS brought me in, showed me behind the curtain – opening up its unique innards for me to peruse, and then let me try it out for myself in a room that is about 8′ x 6′. I was amazed at how quiet the weapon was and how I didn’t experience any blowback of gas.

Fast forward to late last week and we saw the first glimpse of the new MR762A1-SD. For those of you unfamiliar with the SD suffix that is German (Schalldämpfer) which means suppressor. In addition to the suppressor, the rifles also integrate a new Modular Rail System that looks to be related to the open source KeyMod system. Although, the ‘keyholes’ face the wrong direction for KeyMod. As with KeyMod, the MRS is said to have indentations at the rear that lock accessories in place so that they won’t walk under fire. A couple of other things we now know about the MRS. It’s octagonal like the suppressor it shields. This helps with mitigating the effects of mirage. Additionally, we now know that the 556 version is offered in 9″ and 14″ variants and the 762 model boasts 14.7″.

40 years after the after the introduction of the HKMP5 SD, HK introduces the NEW MR556 SD and MR762 SD. The new SD design incorporates OSS suppression technology on the combat proven 416/417 Operating Systems. The OTB “over the Barrel” and “flow through” design aspects of OSS suppressor integration maintains the legacy SD aspects of maximizing the tactical aspect of suppression while minimizing an increase to the weapons overall length. In addition to these HKSD benchmarks, the new SD’s add; caliber and configuration modularity, individual suppressor component sustainability, greater than 90% reduction in blowback and bolt velocity increase, unprecedented accuracy, repeatability and durability. Welcome to the next generation of weapon suppression.



MR556A1-SD

MR762A1-SD

Tags: H&K, Operators Support Systems