SSS.6.77 - Research Supplement: The Rugged Razor556 vs. Razor762 with 7.62mm and 5.56mm Endcaps on the MK18 (Article Preview)

The Rugged Razor556 vs. Razor762 with 7.62mm and 5.56mm Endcaps on the MK18 5.56x45mm AR15 with 10.3-in Barrel

The Rugged Razor556 centerfire rifle silencer is compared to the Rugged Razor762 in this members-only Research Supplement. Parameters investigated are relative First Round Pop (FRP) and overall sound signature suppression performance characteristics on the MK18. Performance of the Razor762 with the standard 30 caliber endcap, as well as the standard Rugged 5.56mm endcap is highlighted, as was done in previous Member Research Supplement 6.59.

Note that the Rugged Razor556 endcap is unique to the Razor556 and not available for purchase separately. It is part of the holistic Razor556 design.

In the analysis, Rugged Razor design change impacts to the PEW Science Suppression Rating (Figure 1) on the standard PEW Science MK18 test host weapon system are investigated. Suppression Rating Rankings for other silencers can be found in Section 7 of the Standard.

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Fig 1. PEW Science Suppression Rating Scale

Test data and analysis for the below rifle silencers on the MK18 host weapon have been published by PEW Science, to date:

• Surefire SOCOM556-RC2 (6.52)

• SilencerCo Saker 556 (6.53)

• HUXWRX HX-QD 556 (6.54)

• Rugged Razor762 (6.58)

• Rugged Razor762 Endcap Research (6.59)

• KGM R556 (6.60)

• Q Trash Panda (6.61)

• HUXWRX HX-QD 556k (6.64)

• RC2 vs. HX-QD 556 Research (6.65)

• CGS Helios QD (6.66)

• RC2 vs. Helios QD Research (6.72)

• Surefire SOCOM762-RC2 (6.73)

• Otter Creek Labs Polonium (6.75)

• Rugged Razor556 (6.76)

• Rugged Razor556 vs. Razor762 (6.77; this article)

Sound suppression performance of 30 caliber centerfire rifle silencers, on 5.56x45mm host weapons with reciprocating (automatic and semiautomatic) actions, is of interest to many weapon system operators. In addition to their multiple-cartridge size utility, 7.62mm bore silencers often possess higher flow rate (lower back pressure) than 5.56mm bore silencers of similar size and design envelope. This so-called over-bore may result in sound suppression performance degradation on 5.56x45mm platforms with some designs. Such performance degradation was highlighted in the previous testing and analysis of the Rugged Razor762 with its standard 30 caliber endcap on the MK18. Previous Member Research Supplement 6.59 evaluated the Razor762 fitted with the standard Rugged 5.56mm endcap on the MK18. Concurrent with this publication, the Razor556 is evaluated on the MK18 (6.76). Public Suppression Rating data is summarized in Figure 2.

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Fig 2. Suppression Rating Comparisons Of The Rugged Razor With The OSS HX-QD 556, Saker 556, And SOCOM556-RC2 , Using PEW-SOFT 5.56x45mm Supersonic Test Data

Typically, silencers possessing a low Omega Metric exhibit low flow restriction (back pressure) which may result in improved sound signature suppression performance at the shooter’s ear on automatic weapon systems such as the MK18. However, when over-bore is significant enough, and flow rate reduction is achieved only through this simple mechanism, the severity of the muzzle signature from the weapon system may significantly impact the signature measured at the shooter’s ear.

It is also important to note that the holistic design of a silencer influences its performance on a weapon system; bore size is only one parameter. The Razor556, like the Razor762, is over-bored for the 5.56x45mm cartridge. However, as discussed in Review 6.76, the Razor556 possesses other design features not present in the Razor762, to include:

• Different baffle quantity (one less baffle).

• Different baffle spacing.

• Different endcap orifice geometry.

The above design differences change the performance of Rugged Razor556 rifle silencer on the MK18 weapon system. The impacts of these design changes have been quantified by PEW Science.

This research supplement is intended to provide more information to PEW Science members with regard to the specific sound signature characteristics of the Rugged Razor556 on the MK18 compared with those of the Razor762 with its standard 30 caliber endcap and 5.56mm endcap. This supplement is part of ongoing PEW Science small arm weapon system sound signature research.

The full version of this article is only available to members. You can support PEW Science testing, research, and development with a membership, here. State-of-the-art firearm sound signature testing and research conducted by PEW Science is supported by readers like you. Thank you for your support!