GEMTECH GM-45 Silencer Review

GEMTECH GM-45 Silencer Review Is the GEMTECH GM-45 a good silencer? There are a few key features that are important to me when determining how good or bad a pistol silencer: […]

GEMTECH GM-45 Silencer Review

Is the GEMTECH GM-45 a good silencer?

There are a few key features that are important to me when determining how good or bad a pistol silencer:

  • Sufficient sound reduction to make shooting hearing safe
  • Cost within reasonable range
  • Durability
  • Ability to use on multiple pistols

The more key features a silencer has, the better fit it is for my needs. However, a silencer can still be worthwhile if it doesn’t meet all of these criteria. Your needs will be strongly influenced by your intended usage. Since at Gear Report we always have a stream of new pistols, rifles and firearms accessories in various stages of testing, I tend to prioritize Durability and Ability to use on multiple firearms a bit higher than some might. While cost isn’t an issue for us since manufacturers send silencers for us to review, it is part of our criteria since cost plays an important role in most consumer’s buying decisions. Making the shot hearing safe is probably the most obvious feature, but also the hardest to test accurately. Since, like nearly every reviewer, we don’t own the $20k+ audio testing equipment required to accurately test true sound suppression levels (no, a phone app or $20 Amazon sound meter that most reviewers use aren’t an accurate way to measure), we simply judge whether it feels hearing safe. ie. How loud does it sound relative to other firearms and silencers. Do our ears hurt or ring after the shot. Not the most scientific method, but it is a very practical, real-world assessment.

With those criteria in mind, the GEMTECH GM-45 is rather impressive, although not without some initial disappointment.

Review Video

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Links mentioned in the video

How GEMTECH describes the GM-45 Silencer

Gemtech GM-45 silencer review - unbox“GEMTECH’s new GM-45 suppressor utilizes our patented G-Core technology. The G-Core design is exceptionally user friendly and allows the user to clean the entire unit. The GM-45 is shipped with the standard .578-28 piston with other several options available.  MSRP $699

Also compatible with 9mm, 40S&W (dry only) and 10mm (dry only)”

Caliber 45ACP
Sound Reduction 23dB dry, 35dB wet
Diameter 1.375″
Length 6.2″ (without mount)
Weight In Units 5.5oz (without mount)
Mount All GM-45 suppressors are shipped with a .578-28 standard piston
Material Aluminum
Full Auto Rated Yes
Finish Matte Black Cerakote with Reduced Visual-IR Signature

Gemtech GM-45 silencer review - Marlin Camp 45 carbineDoes the GEMTECH GM-45 work well?

Yes, it does… when used properly.

Honestly, I hate to admit that I screwed the GM-45 on my Ruger SR-1911 with threaded Storm Lake barrel and was immediately unimpressed. I thought something was wrong with the can, as the 230 gr Defender Ammunition Company .45 ACP rounds were consistently well above “hearing safe” levels. Of course, in a hurry to try the new silencer I had rushed straight from the SOT to the shooting range and not bothered to read the manual.  When I got back to the office and tracked down the instruction sheet I saw the big difference in sound reduction wet vs dry. The manual clearly says ” WET SOUND REDUCTION: 32-35 dB, DRY SOUND REDUCTION: 21-23 dB” I was shooting the GM-45 dry with the relatively hard to silence 45 ACP round.

Grease is the word

On my next trip to the range I knew I needed some grease (petroleum jelly, white lithium grease) to put around the hole on the first G-Core baffle to run the GM-45 “wet”… but I left the grease sitting on the workbench. Determined to try something I squirted some CLP in the can and let it drain down towards the first baffle. There was a noticeable reduction in sound AND the smoke plume that came from the muzzle was friggin’ GLORIOUS!

Finally, I remembered to put some grease on the first baffle before leaving the office (since, apparently, I’m not smart enough to remember to take the grease with me to the range) and found that it did a surprisingly good job of further reducing the sound of each shot, without the entertaining, yet embarrassingly large smoke screen that the CLP created. We didn’t attempt to measure the sound levels with objective audio level measuring tools. My moderately trained ears were happy when running the GM-45 with either grease or CLP.


One of the really cool things about larger caliber pistol cans is that they can be used on a variety of smaller caliber. I tested the GM-45 on both .45 ACP and 9mm pistols and was generally pleased with the results.

  • Ruger SR1911 full sized pistol with Storm Lake drop-in threaded SS barrel: The GM-45 did an great job quieting 230 gr ball rounds… when I remembered to run it wet. First round pop was noticeably quieter when running wet as well. I was surprised that the GM-45 even did fairly well at suppressing the report of the light and fast Ruger Polycase ARX Inceptor ammo (118 gr, 1307 fps advertised… a full 181 fps above subsonic). I tested; 230 gr ball ammo from Defender Ammunition Company, Sig Sauer; 118 gr ARX Inceptor from PolyCase; as well as a few rounds of Gorilla Ammunition 230gr Silverback defensive ammo. The Ruger SR1911 functioned fine with the GM-45 attached via the Gemtech LID device with all ammo tested. While formal accuracy testing was not done with each ammo with and without the can, my informal observation is that the GM-45 generally produced minimal POI shift at typical defensive pistol distances (7 yards or less).
  • Glock 17 full sized pistol with Lone Wolf threaded SS barrel: Sized to accommodate the larger .45 ACP round, the GM-45 is not optimized for 9mm. If you want a can made specifically for 9mm, check out the GM-9. My expectation was for a noticeably louder report when shooting the smaller 9mm round. I was not sure that 9mm would be hearing safe.  However, shooting the GM-45 on the Glock 17 with subsonic 147 gr ball ammo did not make my ears ring. Even running dry first round pop was far less of an issue with 9mm than it was with .45 ACP. I tested; 115 gr ball ammo from Defender Ammunition Company, Sig Sauer; 65 gr PolyCase Inceptor ARX (at a whopping 1620 fps); 124 gr RNFP Competition rounds from Defender Ammunition Company; 147 gr ball rounds from Defender Ammunition Company, Sig Sauer. The Glock 17 functioned fine with the GM-45 attached via the Gemtech LID device with all ammo tested. While formal accuracy testing was not done with each ammo with and without the can, my informal observation is that the GM-45 generally produced minimal POI shift at typical defensive pistol distances (7 yards or less). We have a couple of 9mm AR15s on our upcoming review calendar. Looking forward to seeing how the GM-45 performs with the 9mm ARs.
  • Subsonic 300 Blackout AR15: This is where things went from fun to REALLY fun. The GM-45 is a pistol can, but is rated to safely handle subsonic 300 Blackout rifle rounds. This is an important distinction, as it is not rated for supersonic 300 Blackout. Fortunately, we shoot a LOT of subsonic 300 BLK and were able to test the GM-45 on AR15s in pistol and rifle configurations. The rifle also has a SlideFire stock, which lets us run through a full magazine in a few seconds. In all configurations the GM-45 silencer performed rather well on the AR15s. Since the can is set up for .45 and the 300 BLK shoots a 30 cal projectile, the first round pop and back pressure were both pretty tame. Overall, audible reduction of report is impressive, making the 300BLK hearing safe. We tested subsonic 220 gr ammo from Defender Ammunition Company, Sig Sauer and Gorilla Ammunition Company. All performed well.
  • Ruger 10/22 Takedown Lite: I might not have thought to try a .45 caliber silencer on a .22 lr rifle were it not for a comment from Alexander at GemTech. He said it does a great job on .22 and I am thrilled to report that our testing confirmed this. Running standard (which is actually subsonic) or branded “subsonic” 22lr ammo through the Ruger 10/22 Takedown Lite took the report of the diminutive 22 long rifle round from a sharp crack to a mild pop. Back pressure venting hot gas into the shooter’s face was not a problem, as it can be with blowback operated firearms.

    Gemtech GM-45 silencer review - Ruger 10/22 Takedown Lite

    Shooting the 10/22 Takedown Lite with Gemtech GM-45 silencer

  • Savage MKIII bolt action rifle: We saw slightly better results in the Savage vs the Ruger 10/22. This is to be expected since the bolt stays closed until all pressure has bled off in the chamber and barrel, where the bolt opens prior to all pressure bleeding off in a semi-auto. We ran standard and subsonic ammo and both did great.
  • Marlin Camp 45 Carbine: The one firearm that let us down with the GM-45 was the Marlin Camp 45 Carbine. Adding a silencer to the combination of the blowback action with the 16″ rifle barrel and fast burning pistol powder in the .45ACP rounds resulted in the bolt opening too early and hot, burning gun powder being shot back into the face of the shooter. You can’t blame the GM-45 for this issue, as it really just illustrates that you can’t throw a can on any firearm and expect it to operate like it was designed to be a silencer host. My first instinct was to cook up some 45ACP rounds with a slower burning powder. However, I quickly realized that my knowledge of load development is a bit lacking for this endeavor and abandoned that idea. Rather than delay the pressure spike that opens the blowback action, I opted to beef up the spring that holds the bolt closed. Grandmasters LLC was kind enough to supply a variety of parts to upgrade the Marlin Camp 45.

Is it hard to buy a silencer… You know… legally?

I wouldn’t say it is “hard”, but it is a multi-step process. It can take a few hours to gather all of the info, pictures, etc. required for the ATF Form 4 transfer. Once the form is sent to the ATF it can take 6 months, or even 12+ months to get approved, then a month or so for the AFT to get around to sending notice of approval to your local SOT FFL. Gemtech has a nice overview of how to buy a silencer here.

I’ve been through the process a few times and found it frustrating since there is no real-time tracking of your Form 4. It can sit for months before assigned to someone for processing. Waiting isn’t fun. It doesn’t help that NFA rules in general, and especially for gun mufflers makes even less sense than most of the AFT rules and policies (which is saying something). Like it or not, until the laws are changed, it is what US Citizens have to do if we want to own a silencer. Honestly, waiting is the hardest part… well, after accepting that we really do have to follow the unconstitutional NFA rules.

The biggest secret to completing the Form 4 process is to actually SUBMIT THE FORM 4. ie. Don’t put it off because you are afraid of a little paperwork. It is easier than doing your taxes. The sooner you start, the sooner you will finish. It also helps to be thorough and detail oriented when filling out the Form 4.

How to attach the GM-45 to a rifle or pistol with  non-moving barrel

GM-45 Threaded Rear Mounts


Threaded End Cap adapters for use with the GM-45 and Blackside suppressors. These allow the use of the suppressor on Fixed barreled weapons.

Choose between:

  • 0.578-28 (45 ACP Carbines)
  • M16x1LH (45 ACP Carbines, KRISS)
  • 5/8-24 (300 BLK)
  • 9/16-24 (for use with .40 S&W)
  • 1/2-28 (9mm Carbines)
  • 1/2-36 (9mm Carbines Colt, RRA, Bushmaster)
  • M13.5x1LH (9mm Carbines/ Sub Guns)
Retails for $85.00

How to attach the GM-45 to a semi-auto pistol with  moving barrel

Piston for GM-45 and Blackside-45 LID



An extra LID Piston Core allows you to easily change threads on a GM-45 or BLACKSIDE-45 to use one suppressor on either U.S. standard threaded pistols (0.578-28) or with European (Metric) threaded pistols. Not only does the pistons let you use your suppressor on your .45 suppressor, but with our other options you can also use them on 40 caliber and 9mm pistols. All options can be installed in the field without the use of tools.

Gears Rating:

Gear Score
The GM-45 has proven to be a versatile, durable and dependable silencer on a wide range of pistols and rifles and with various ammunition types.

Ammo for testing provided by

Without the support of our ammo suppliers we would not be able to do nearly the amount of gun reviews that we do today.

Defender Ammunition CompanyDefender Ammunition Company

Big thanks go to our primary Ammo Sponsor Defender Ammunition Company for supplying ammo for our tests and reviews on an ongoing basis. Defender provided a variety of calibers and types of ammo for this test.

Sig Sauer

SIG provided a wide range of practice and defensive ammo for this test.

Gorilla Ammunition

Gorilla Ammo provided reman and factory rifle rounds, as well as some defensive ammo for this test.

Ruger FirearmsRuger / Polycase

PolyCase and Ruger provided various flavors of ARX ammo for this test.

About Jeff

Jeff is the Editor in Chief of Gear Report and a National Shooting Sports Foundation Media member. He reports on the outdoor industry, reviews gear for camping, hiking, shooting, hunting, paddling, backpacking and other active pursuits. A USAF veteran, Jeff earned a MBA in Marketing and Health Services. He specializes in consultative selling and internet marketing. As the VP of BD & Marketing, Jeff provides sales and marketing leadership to MGECOM, Inc. and helps acquire new clients in need of solutions for online merchants in need of Affiliate Marketing program management. Jeff founded and manages Cress Sales & Marketing LLC, offering online sales and marketing consulting and services to online merchants and service providers.