The CGS Group SCI-Six in FDE Cerakote — a 3D-printed Inconel 718 5.56 NATO rifle suppressor co-designed with Irregular Defense and rated for machine-gun-pace fire.
The SCI-Six is the product of a three-party collaboration: CGS Group's suppressor design team, Irregular Defense (whose principals include former Naval Special Warfare operators), and the shooters testing hardware at the muzzle. The design brief was narrow — a 5.56 NATO can sized for a short-barrel carbine, low on first-round pop, low on gas blowback, durable enough to absorb drops in the desert or contact with vehicle and airframe hardware. Every geometry choice traces back to that brief.
Construction is Direct Metal Laser Sintering of Inconel 718 — the same high-nickel alloy used in turbine hot sections. DMLS builds the baffle stack as one continuous piece, removing the weld lines that are the usual failure mode on welded-baffle cans. More importantly, it lets CGS place venting and geometries that a milling or lathe operation cannot produce. The blast chamber on the SCI-Six vents early into an annular path under the outer skin, then forward and out the cap — a patented CGS Group flow path common across the company's centerfire rifle line. The net effect is lower back pressure into the rifle and less gas pushed back at the shooter.
Mounting is via a proprietary reverse-thread muzzle device with a tapered seat. The taper lineage traces back to the Ops, Inc. over-the-barrel mount that is part of the Mk12 SPR's signature footprint; Sig and Q have run taper-mount designs more recently. The taper-seat seals on cone contact rather than on a 90-degree shoulder, which means a barrel that is not perfectly faced at the threads still indexes and locks repeatably. Zero shift between sessions is what the design is chasing.
Third-party testing from Pew Science places the SCI-Six at a 34.7 suppression rating and 149.7 dB at the shooter's ear on a 10.3" Mk18 rifle, putting it in the same performance band as the Surefire RC2 and HUXWRX OSS cans, and ahead of the Knight's Armament NT4, the SilencerCo Saker 556, and the Sig SRD 556. Sound reduction is one variable of many — back pressure, flash signature, weight, and durability all matter on a duty can — but the data is publicly available and worth reading.
The FDE finish is a commercial choice rather than a program spec. CGS delivers the Ion-bonded DLC suppressor, which goes back to the Cerakote shop for FDE; customers who want the baseline black Ion-bonded finish can order that variant instead.
NFA item: this suppressor must ship to an FFL/SOT dealer — no civilian exceptions. Verify your state allows the transfer before ordering. Have your dealer email a copy of their FFL and SOT to Charlie's; expect to hear from our compliance team within 3–4 business days. See the Pew Science sound review of the CGS SCI-Six for the full test data.
We keep these in stock when we can. Reach out if the color or mount config needs tweaking — we will square you away.
THIS IS A SERIALIZED ITEM. It must ship to a Federal Firearms License holder. No civilian exceptions.
Buying and shipping through Charlie’s is easy, but there is some information you need to know. Only a federally licensed firearms dealer may receive a firearm or federally regulated serialized item (like a receiver or suppressor). We cannot ship these items directly to you. Please follow these steps to process your transaction:
1) Check your state laws to make sure the federally regulated item you want to purchase is legal in your state. Your FFL dealer should be able to give you all of the necessary information regarding your state specific laws. But, if we ship to your FFL, and there is a legal issue, we cannot accept a return. So please make sure that you know and follow your local and state laws.
2) A quick google search will show you what Federal Firearms Licensed (FFL) dealers are in your area. When you are ready to purchase, contact the FFL dealer you would like to use and get their shipping address. During the check-out, put YOUR address in the “billing” section and the FFL DEALER’S address in the “shipping” section. If you don’t know your FFLs address, that’s okay. You can send the information later.
3) After check out, make sure to contact your FFL dealer to ensure they will receive your shipment for you (most do this for a small fee, but you should always double check).
4) Have your dealer send us a copy of their FFL to FFL@CharliesCustomClones.com. Charlie’s does not reach to your FFL (MAKE THEM EARN THEIR FEE!!!)
5) Be patient! In order to ensure we remain compliant with all federal laws, our compliance department is kept separate from our sales and operations team. Please allow a few days for our compliance officer to verify all of your dealer’s documents and ensure all federal laws are being observed. You should hear from our compliance department within 3-4 business days. If not, feel free to reach out for a status update.
That’s it! We try to make this process as simple as possible for our customers, but if you are unfamiliar the process or have any other questions, please visit our How to Buy a Suppressor page for more details.
