H&K MR556-SD MR762A1-SD with Modular Rail System & OSS Suppressors

    Rob Curtis published a product brochure for the upcoming not-yet-announced H&K MR556-SD MR762A1-SD. The H&K MR556-SD MR762A1-SD features a new Modular Rail System (MRS) that allows rails segments to be screwed in where required, much like the KeyMod system. The suppressors are interesting. Rob writes

    The OSS suppressor system also improves the HK platform by adding caliber and configuration modularity, individual suppressor component sustainability, greater than 90% reduction in blowback and bolt velocity compared to competing suppressor systems. The OSS system comprises a back pressure regulator (BPR) and a sound reduction module (SRM). The rifle is shot ‘unsuppressed’ with the BPR installed. This reduces flash and noise noticeably, but the addition of the SRM will reduce the muzzle noise to 139db at the shooters ear.

    These guns will be available for sale to consumers.


    Steve Johnson

    I founded TFB in 2007 and over 10 years worked tirelessly, with the help of my team, to build it up into the largest gun blog online. I retired as Editor in Chief in 2017. During my decade at TFB I was fortunate to work with the most amazing talented writers and genuinely good people!