Military Times の GearScout によると、Heckler & Koch が HK416 と HK417 のセミオート仕様民間版、MR556 と MR762 に KeyMod システム対応のハンドガードを備えた SD モデルを新たに加わえたとのこと。新型 SD モデル "MR556A1-SD" と "MR762A1-SD" のデザインは、米国でサプレッサー開発を手掛ける Operators Suppressor Systems (OSS) 社との協力でおこなわれている。(以下、プロダクトシートに記された「MR556A1-SD」の仕様に関する内容)

Important Features of the MR556A1-SD
[Modular Rail System (MRS)]
* Repeatable rail segment mounting in any position along the 14 inch forearm (9 inch MRS also available
* Self-captured rail segment hardware
* Two integrated Quick Detachable (QD) sling attachment points just foreward of the receiver
* Optional positionable QD mount attachment
* Octagon profile allows the OSS suppressor to be installed / removed with rail in place
* MRS provides more comfort to the shooter's support hand

[OSS SUPPRESSOR]
* Typical 18 dB reduction with the BPR module installed without SRM
* Less than an inch ofincreased weapon length with iustthe BPR
* Eliminates up to 95% ofthe back pressure created by traditional suppressors
* Attenuates the noise signature without adversely affecting the operating system
* Redirection of expanding gas within the BPR reduces felt recoil and muzzle rise
* Greatly reduces weapon fouling
* Little increase in bolt speed
* Reduces component wear and overheating common to legacy suppressor designs
* Reduction in back pressure greatly diminishes toxic gases expelled back at the shooter
* Better weapon balance with overthe barrel mounting ofthe BPR module
* Typical sound reductions measured at the shooter's ear with the BPR and SRM4 installed (139 dB
* Components are designed to self--tighten during firing to prevent loosening
* Little to no impact shift transitioning from just BPR to BPR and SRM
* Typical MRTF (mean rounds to failure) 8000 rounds, semi--automatic
* Internal parts on both the BPR and SRM can be replaced

Gerar Scout / Military Times 2014/01/07