The High Standard HD Military pistol is considered the benchmark for suppressed pistols among intelligence agencies and clandestine organizations.

It was initially adopted by the renowned Office of Strategic Services in early 1944 and was utilized in all World War II theaters. The pistol proved to be so efficient that the CIA continued to use it until at least 2001, and it is likely that it remained in service even after that.

High Standard HD Military Suppressed Pistol

While in the development phase, the engineers at OSS employed a range of innovative techniques to minimize both the sound of the pistol’s mechanical action and its report. They experimented with using 22LR bullets made of gold and tungsten, as these denser metals helped to reduce the bullet’s velocity.

After numerous attempts, the ideal combination of velocity, recoil, and reliability was achieved by modifying the pattern and number of holes drilled into the barrel.

How many decibels is the high standard HDM? When paired with the appropriate ammunition, the pistol’s integrated suppressor enabled it to generate only 77 decibels of noise, equivalent to the sound of a muffled cough.

Undoubtedly, the HD Military Suppressed pistol was an efficient weapon for assassination.

Areas of Operation

By July 1944, approximately 1,400 High Standard HD Military Silencer pistols had been dispatched to the European, Mediterranean, and Far East theaters of operation, with the British Special Operations Executive also issuing them to their agents.

The Alamo Scouts, a renowned military unit in the Pacific Theater of Operations, acquired six model HD MS pistols. They utilized the weapons mainly for removing sentries and acquiring food during extended missions without any chance of resupply.

The French Resistance and other guerilla groups were among the beneficiaries of the High Standard HD Military Silencer pistols, which enabled them to assassinate enemy soldiers and vanish quickly into the local populace without drawing any attention. In urban settings, the model HD also proved to be useful in discreetly disabling streetlights to create a cover of darkness.

Following the conclusion of World War II and the dissolution of the OSS, the newly established Central Intelligence Agency took ownership of the High Standard Suppressed Pistols. The CIA modified them by including a .22 short magazine in addition to the .22 LR magazine and started distributing them to their case officers.

The High Standard HD Military Silencer was a favorite among the MACV-SOG teams, who carried a range of American-made and foreign weapons during their covert missions. The High Standard was a critical component of their arsenal.

In the year 2000, the Marine Corps 1st Force Reconnaissance Company still possessed ten High Standard HD suppressed pistols in their armory. It’s probable that some other clandestine organizations still have a few of these weapons in their possession as well.

As the firearms and defense industries evolved over a few decades, so did the design of the High Standard HD suppressed pistol. Maxim Defense is one of those companies bringing back an insanely effective suppressed pistol for the military, clandestine agencies, and even you and I.

Enter the Maxim Defense Ruger MkIV-SD

The creation of the Maxim Defense integrally suppressed Ruger MkIV originated from the High Standard HDM, a .22 pistol with an integrated suppressor utilized by the OSS during WWII. The OSS was in need of a compact and remarkably silent pistol for their undercover field operations during the Second World War.

The design featured a barrel with ports and a diffuser that helped slow down the speed of supersonic ammunition to subsonic levels. The suppressor section of the firearm was made up of a mixture of copper mesh and straightforward baffles.

One benefit of the Hi-Standard OSS pistols is that they allow the operator to use standard ammunition instead of having to find and carry specialty subsonic ammunition. Dr. Philip H. Dater was a fan of these pistols and began creating his own version of Ruger Mk-II/III pistols in the 1960s, using in-house designed K baffles while working at Automatic Weapons Company (AWC). He continued making these pistols until the 1980s and 1990s when he started the company Gemtech (Gemini Technologies, Inc.) and began producing them more seriously.

Dr. Dater incorporated modern and efficient components into his integrally suppressed Ruger Mk-II/III pistols, which he called the Quantum, and enjoyed success with this product at Gemtech until the company ceased to exist in its original form. In early 2019, most of the Engineering and R&D staff from Gemtech were hired by Maxim Defense, and Dr. Dater joined the team there as well.

One of the early R&D projects at Maxim Defense was to modernize the OSS/Quantum and address the design’s strengths and weaknesses. The biggest issue was with the K baffles, which tend to get dirty and stuck in silencer tubes, making cleaning and maintenance difficult. To address this, Maxim Defense designed a monocore that is easily removable and has robust tool features, encouraging maintenance and ensuring optimal performance.

Maxim Ruger Mk IV-SD

Features and Specs

  • No detectable first-round pop!
  • Drops sound to well below hearing safe levels (specific reduction based on ammunition and atmospheric conditions). Average measurement per MILSTD-1474D of 114 dB average with Gemtech subsonic ammunition and 123dB with CCI Minimag ammunition. These measurements are from the shooter’s left ear measurement location.
  • Caliber: 22LR
  • Material Composition: 7075-T6 Aluminum and 4140 steel
  • Finish: Nitride / Type II hard coat anodizing
  • Weight: 3.5 ounces (integral suppressor)
  • Length: 12.6″ overall length of the weapon
  • Diameter: 1.0″ outer diameter (integral suppressor)
  • Barrel Length: 3.75″

Is the Maxim Defense MKIV-SD The new High Standard HD?

After completing the most challenging aspect of the redesign, Maxim Defense finished the remaining components and optimized the diffuser for standard velocity ammunition, eliminating the need for specialized subsonic suppressor ammunition. However, there was still one aspect left to address: the sights. The R&D team recognized that the future of all pistols involved the ability for factory pistols to mount optics and lights/lasers.

Maxim Defense developed a series of optic mounts that replace the rear sight in the receiver without requiring any modification to the receiver itself. These mounts keep the optic as low as possible and offer different options, such as 1/3 co-witness backup iron sights or a simple mount for a red dot. The two-piece design also allows users to attach a light or laser underneath the suppressor tube using a piece of M1913 Picatinny rail if they so choose.

Ruger MKIV Integral Suppressor

Thanks to these design improvements, the Maxim Defense Ruger MkIV-SD, when using Federal standard velocity ammunition and measured according to MILSTD 1474-D/E military manual standards, typically produces a noise level of 114dB, and sometimes even less on a particularly good day. Additionally, this pistol produces very little to no gas blowback for the shooter and feels comfortable to hold.

The Maxim Defense Ruger MkIV-SD represents the pinnacle of integrally suppressed .22LR pistol design and is arguably one of the best designs currently available on the market.

Advantages of the Integrally Suppressed MKIV-SD

By incorporating its 22 suppressor design directly into the barrel of the Ruger Mark IV, Maxim Defense has elevated sound suppression to the next level.

Integrally suppressing a barrel provides several benefits over using a direct thread or quick-attach suppressor.

  • Improved Accuracy – One of the main advantages of an integral suppressor is its inherent design, which eliminates impact shift and enhances accuracy. If you have ever switched an external suppressor between different firearms, you are aware of how it can affect the point of impact, necessitating the need to re-zero your red dot or scope.
  • Compactness – Aside from the issue of variances in bullet impact, detachable suppressors also add size and weight to firearms. When adding an external suppressor to most firearms, it is often necessary to use suppressor height sights or taller scope rings. However, by opting for the integrally suppressed Ruger Mark IV from Maxim Defense, the overall diameter of the barrel does not add any height. As a result, in most cases, you can continue using your current optics without any adjustments needed.
  • Ergonomics – Integrally suppressed firearms have the advantage of being shorter, lighter, and better balanced than the same firearms equipped with detachable suppressors since the suppressor is built into the barrel. Additionally, the ergonomics of the firearm are greatly improved with the integral suppressor design, from the balance, handling, and overall feel to the ease of use.

In Conclusion

The High Standard HD Military pistol was a revolutionary design that paved the way for modern integrally suppressed firearms.

With the advent of the new Maxim Defense MkIV-SD integrally suppressed pistol, this design has been brought into the 21st century with a range of enhancements and improvements. The result is a firearm that is both incredibly effective and enjoyable to use, offering exceptional accuracy, reduced sound levels, and improved ergonomics.

Whether you’re a seasoned shooter or just starting out, the Maxim Defense MkIV-SD integrally suppressed pistol is a game-changer that is sure to impress.

Stay Tuned to the RE Factor Tactical Blog and be part of this all VETERAN-run website. Be sure to follow us on FacebookInstagram, and LinkedIn for exclusive content and deals.

Check out our DAILY DEALS page for industry deals and discounts.

Visit our Amazon Influencer Page for more products we recommend: