Strategic Sciences MFMD Buying Guide
The Multi-Function Muzzle Device (MFMD) is a flash hider, muzzle brake and suppressor in one. Here's how it works, how to read the model names, which model fits your rifle, what the test data shows, and answers to the questions we get asked most.
What the Strategic Sciences MFMD Is
Most rifles wear one muzzle device at a time, so you pick a flash hider, a brake or a suppressor. The Strategic Sciences Multi-Function Muzzle Device (MFMD) does all three in one device that threads directly onto your barrel.
The base unit is the MD (muzzle device), and the MD is the suppressor. Two optional modules, the SD (Suppressor Device) and SDX (Suppressor Device Extended), lock onto the front of the MD for more sound and flash reduction. Pull the module off and the MD stays on the rifle as your flash hider and brake.
Strategic Sciences is in Salt Lake City, Utah. Its CEO, Russ Oliver, designed the MFMD. He's a former Green Beret, and he founded OSS, the suppressor company now known as HUXWRX. See our HUXWRX buying guide for that lineup.
We carry three MFMD models: the 5.56 MFMD, the 300 BLK MFMD and the 7.62 MFMD. Each one comes in several options, and the option names take some decoding. We break that down in model names.
Why Shooters Choose the MFMD
The MFMD isn't a typical suppressor. Here's what you get with it:
- Flash, sound and recoil from one device. With the SD module on, lab testing on the rifles in this guide shows 90% to 99% less peak flash, 27% to 63% less rearward recoil force, and 17 to 33 dB less sound at the shooter's ear. See the lab data.
- Your gas gun keeps its tune. Bolt velocity stays within ±2% of the unsuppressed rifle on every tested system. Bolt velocity is how hard the action cycles, so it's the number that tells you whether a suppressor over-gasses your rifle. You don't spend an afternoon re-tuning after you put the MFMD on.
- Built for night vision. With the SD module on, five of the tested rifles measured 0.01 lux of peak flash. With their issued flash hiders, those same rifles measured up to 2.82 lux.
- Less added length. The OTB models reach back over your barrel instead of only out past the muzzle. A 14.5 in. barrel with an MFMD can match the overall length of a 10.3 in. barrel with a conventional suppressor, so you keep the longer barrel's velocity.
- Military durability. The MFMD is built to last as long as a barrel, and all three of our models are full-auto rated.
- Independent results. On a .308, PEW Science found that the 7.62 MFMD with the SDX "outperforms every tested silencer in the research in blast overpressure suppression, to date." See PEW Science testing.
- A military development program. The MFMD started in March 2022 as an Irregular Warfare Technology Support Directorate (IWTSD) task order, requested by Canadian, U.S. Navy and Australian special operations commands. In February 2026, it completed a Phase II Government Inspection and Performance Verification. Read the program history.
How the MFMD Works
Gas flow instead of a baffle stack
A conventional suppressor traps gas in a stack of chambers in front of the muzzle. The MFMD keeps the gas moving. Four internal flow paths spin it away from the muzzle in opposing directions, folded into more than 10 feet of flow path inside a 4.5 in. device, and the gas vents forward. You can watch it happen in the 10,000 frames-per-second footage on the MFMD lab pages.
Venting forward is how the MFMD keeps bolt velocity within ±2% of the unsuppressed rifle. PEW Science called "the high early time flow rate, controlled blast propagation, and recoil control of the MFMD" strong performance traits.
Inconel, 3D printed
The MFMD is 3D printed from Inconel 718, a nickel-based alloy. Inconel won't spark or burn the way titanium can, so the material itself is part of the flash reduction. The MFMD is one piece and can't be taken apart.
Over-the-barrel (OTB) design
Most MFMD models reach back over the barrel. The number in the model name (0.0, 1.3, 2.4, 3.0) is how many inches. That overlap adds suppressor volume without adding overall length, and it moves weight back toward the middle of the rifle. Flush (0.0) models fit rifles with no room behind the muzzle.
Not to scale. Both are drawn the same length to show the difference in position: the OTB model slides back over the barrel, so less of it sticks out past the muzzle. Measure OTB clearance from the barrel shoulder back to the handguard, and leave 3/16 to 1/4 in. of space between the MFMD and the handguard.
If your rifle has the room, go OTB. On 5.56, the 1.3 MD alone measured 138.6 to 139.4 dB at the shooter's ear, compared with 141.9 to 143.1 dB for the flush MD.
Modules that clip on
The SD and SDX lock onto the front of the MD with a retention lever: hook the module in place, cam it onto the MD and close the lever.
One mount, one rifle
The MD installs by direct thread with the included shims and tool. No adapters. It's fitted to your barrel's shoulder, length and diameter, so think of it as a suppressor for one rifle. See fitment.
How to Read MFMD Model Names
There are more than 240 MFMD versions, and every name follows the same pattern. Once you know the pattern, you can read any of them. Here's one from our 5.56 page:
MFMD - 5.56 - 1.3 - MDSDX - 1/2X28
| Part | Example | What it means |
|---|---|---|
| Product | MFMD | Multi-Function Muzzle Device. |
| Caliber | 5.56 | The cartridge it's built for. We carry 5.56, 300BLK and 7.62. The MFMD is made in calibers from 5.56 up to .50 BMG. |
| OTB | 1.3 | How many inches the device reaches back over your barrel. 0.0 is a flush mount (also written 0.0 FM) that starts at the barrel shoulder, with nothing over the barrel. |
| Configuration | MDSDX | What's in the box. MD = muzzle device only. MDSD = MD plus the SD module. MDSDX = MD plus the SDX module. KIT = MD plus both modules. |
| Thread | 1/2X28 | Your barrel's thread pitch. On the models we carry: 1/2x28 for 5.56 and 5/8x24 for 300 BLK and 7.62. |
| Color | BK | Picked separately: BK (Black), FDE (Flat Dark Earth) or GRN (OD Green). We stock Black and FDE. |
Extra letters you may see
Some names add a tag after the OTB number or the thread:
- N (after the thread, as in 5/8X24N): a notched device. Our 7.62 2.4 is a notched model (MFMD-7.62-2.4-MD-5/8X24N).
- C (after the thread, as in 3/4X24C): a crown mount, for barrels without a standard shoulder. OTB is measured from the crown instead of the shoulder.
- LHC: left-hand threads and a crown mount.
- HB (after the OTB number, as in 3.0HB): built for heavier barrels. The 7.62 3.0HB fits barrels up to 1.08 in. in diameter.
- MG (after the OTB number, as in 0.8MG): built for belt-fed machine guns.
Our option dropdowns use the short form: 1.3 MDSDX - 1/2x28 Black is the MFMD-5.56-1.3-MDSDX-1/2X28 in Black.
MD vs. SD vs. SDX: Which Configuration to Buy
| MD | MDSD | MDSDX | |
|---|---|---|---|
| What you get | Muzzle device (the suppressor) | MD plus SD module | MD plus SDX module |
| Use it for | Flash hider, brake and suppressor in one | Adds the SD module for more suppression | Adds the longer SDX module |
| 5.56 on our site | 0.0 and 1.3 | 0.0 | 0.0 and 1.3 |
| 300 BLK on our site | 0.0 | Not listed | 0.0 |
| 7.62 on our site | 2.4 | Not listed | 2.4 and 3.0 |
- The MD is the suppressor. It suppresses on its own and it's a regulated NFA item, so every version, including MD only, goes on an ATF Form 4.
- Decide on the module up front. The SD and SDX are only sold as part of an MD package (MDSD, MDSDX or KIT), not by themselves. If you think you'll want a module, buy it with the MD.
- The KIT is a two-stamp item. The KIT includes the MD, SD and SDX and takes two approved Form 4s. We don't currently carry KITs.
- Flush models gain the most from a module. On 8 to 10.3 in. barrels, the flush 5.56 MD alone cut flash by 9% to 57%. Add the SD and it's 94% to 98%. On the shortest rifles, get the MDSD or MDSDX.
Which MFMD Fits Your Rifle
Fitment is the most important step with the MFMD. If you don't have the clearance, it doesn't fit. Check three things before you order:
- OTB clearance. Measure from the barrel shoulder back to the first obstruction, usually the handguard. On a tapered shoulder, measure from the end of the taper (these barrels use a Tapered Barrel Adapter). On a barrel with no shoulder, measure from the crown. Leave 3/16 to 1/4 in. of space between the rear of the MFMD and the handguard.
- Barrel diameter. The OTB section slides over the barrel, so the barrel can't be too thick. The maximum is 0.785 in. for the 5.56 1.3 and 0.82 in. for the 7.62 2.4 and 3.0. Flush (0.0) models have no limit because nothing goes over the barrel.
- Thread pitch. 1/2x28 for our 5.56 models and 5/8x24 for our 300 BLK and 7.62 models.
The MFMD Configurator matches models to rifles. Each of our models was optimized and tested on these rifles:
| Model on our site | OTB | Max barrel diameter | Tested rifles |
|---|---|---|---|
| 5.56 MFMD 0.0 | Flush | No limit | Geissele PDW 8 in., Daniel Defense PDW 8 in., Daniel Defense MK18 10.3 in., Geissele URG-I 10.3 in., HK 416 10.3 in. |
| 5.56 MFMD 1.3 | 1.3 in. | 0.785 in. | Geissele URG-I 11.5 in. and 14.5 in., Daniel Defense DDM4 V7S Pro 16 in. |
| 300 BLK MFMD 0.0 | Flush | No limit | SIG MCX Rattler 5.5 in., SIG MCX Spear LT 9 in. |
| 7.62 MFMD 2.4 | 2.4 in. | 0.82 in. | SIG Spear 16 in. |
| 7.62 MFMD 3.0 | 3.0 in. | 0.82 in. | SIG 716 G2 16 in., FN SCAR 20S 20 in. |
Other rifles work if they meet the clearance, diameter and thread requirements. Not sure about yours? Send us a picture of your rifle and we'll check it with you before you order.
MFMD Lab Data by Rifle
Strategic Sciences lab tests MFMD models on specific rifles and publishes the results. Click a rifle to see its page. Each test compares three setups: the rifle's issued flash hider (baseline), the MD alone, and the MD with the SD module. Sound is in dB at the shooter's right ear, flash is peak lux at 90 degrees to the muzzle, and recoil is rearward g-force.
5.56 MFMD
| Rifle | Model | Sound at ear: baseline / MD / MD+SD | Flash cut: MD / MD+SD | Recoil cut: MD / MD+SD |
|---|---|---|---|---|
| Geissele PDW 8 in. | 0.0 | 161.97 / 142.96 / 136.86 dB | 9% / 98% | 34% / 35% |
| Daniel Defense PDW 8 in. | 0.0 | 163.44 / 143.03 / 136.60 dB | 57% / 98% | 35% / 53% |
| Daniel Defense MK18 10.3 in. | 0.0 | 159.56 / 142.64 / 135.46 dB | 40% / 94% | 53% / 49% |
| Geissele URG-I 10.3 in. | 0.0 | 160.67 / 141.92 / 134.36 dB | 33% / 96% | 49% / 49% |
| HK 416 10.3 in. | 0.0 | 158.42 / 143.11 / 135.42 dB | 33% / 98% | 57% / 58% |
| Geissele URG-I 11.5 in. | 1.3 | 162.3 / 139.4 / 135.6 dB | 98% / 99% | 63% / 63% |
| Geissele URG-I 14.5 in. | 1.3 | 159.50 / 138.57 / 135.50 dB | 93% / 99% | 54% / 54% |
| Daniel Defense DDM4 V7S Pro 16 in. | 1.3 | 157.68 / 139.02 / 135.42 dB | 95% / 99% | 54% / 55% |
300 BLK MFMD
| Rifle | Model | Sound at ear: baseline / MD / MD+SD | Flash cut: MD / MD+SD | Recoil cut: MD / MD+SD |
|---|---|---|---|---|
| SIG MCX Rattler 5.5 in., supersonic | 0.0 | 167.26 / 146.78 / 134.04 dB | 4% / 91% | 26% / 27% |
| SIG MCX Spear LT 9 in., subsonic | 0.0 | 154.48 / 140.25 / 128.20 dB | 81% / 90% | 30% / 30% |
7.62 MFMD
| Rifle | Model | Sound at ear: baseline / MD / MD+SD | Flash cut: MD / MD+SD | Recoil cut: MD / MD+SD |
|---|---|---|---|---|
| SIG Spear 16 in. | 2.4 | 157.24 / 142.48 dB / not published | 68% / not published | 43% / not published |
| SIG 716 G2 16 in. | 3.0 | 155.93 / 141.54 / 138.61 dB | 91% / 99% | 47% / 48% |
Our take on the data
- With the SD on, every setup tested with a module measured under 140 dB at the shooter's ear, from 128.20 dB (subsonic 300 BLK) to 138.61 dB (7.62).
- Bolt velocity stayed within ±2% of baseline on every rifle, with the MD alone and with the SD.
- The OTB models do more with the MD alone. The 5.56 1.3 MD cut flash by 93% to 98%; the flush 5.56 MD cut it by 9% to 57%. On flush models, most of the flash reduction comes from the module.
- On the 5.5 in. Rattler with supersonic 300 BLK, adding the SD took sound at the ear from 146.78 to 134.04 dB and flash reduction from 4% to 91%. On a barrel that short, get the MDSDX.
These tests use the SD module. The 300 BLK and 7.62 options we carry come with the longer SDX (Suppressor Device Extended). For SDX results, see PEW Science's .308 test below.
What PEW Science Measured
PEW Science tested the MFMD-7.62-3.0 with the SDX module on a Savage Model 10 Precision Carbine with a 20 in. barrel, firing Federal XM80 149 gr ammo (SSS.6.230). That's the 3.0 MDSDX option on our 7.62 MFMD page.
- Suppression Rating: 62.0.
- Blast overpressure: with the SDX on, PEW Science wrote that the MFMD "outperforms every tested silencer in the research in blast overpressure suppression, to date."
- Length: 7.72 in. forward of the barrel shoulder with the SDX (10.72 in. overall, with 3 in. over the barrel). That's 15% shorter than the PTR VENT 1, which PEW Science calls its flush-mount performance leader, at 9.1 in.
- Weight: 26.4 oz for the MFMD-7.62-3.0 and 15.3 oz for the SDX, 41.7 oz total.
- Size: 2.74 in. tall and 1.84 in. wide.
PEW Science's summary: "The Strategic Sciences Multifunction Muzzle Device (MFMD) is a next generation rifle silencer."
Strategic Sciences MFMD Models We Carry
All three are Inconel, Cerakote finished, direct thread and full-auto rated. Each ships with the MD, a shim kit, the install tool and an instruction manual, plus the module on MDSD and MDSDX options. Shop 5.56 suppressors or .30 cal suppressors.
Strategic Sciences 5.56 MFMD
The 5.56 MFMD fits 1/2x28 AR-15s and other 5.56 rifles, from 8 in. PDWs to 16 in. carbines. It's the only one of our three with both flush and OTB options.
Caliber: 5.56/.223 | Thread: 1/2x28 | OTB: 0.0 (flush) or 1.3 in. | Length: 4.7 in. MD, 7.75 in. with SDX | Weight: 20 oz MD, 34 oz with SDX | Material: Inconel
If your rifle has 1.3 in. of clearance behind the muzzle and a barrel no thicker than 0.785 in., get the 1.3. The 1.3 MD alone measured 138.6 to 139.4 dB at the shooter's ear with 93% to 98% less flash. For rifles with no room behind the muzzle, get the 0.0 and add the SD or SDX for the most flash reduction.
| Option on our site | What it is |
|---|---|
| 0.0 MD - 1/2x28 (Black or FDE) | Flush, muzzle device only |
| 0.0 MDSD - 1/2x28 Black | Flush, MD plus SD |
| 0.0 MDSDX - 1/2x28 Black | Flush, MD plus SDX |
| 1.3 MD - 1/2x28 FDE | 1.3 in. OTB, muzzle device only |
| 1.3 MDSDX - 1/2x28 Black | 1.3 in. OTB, MD plus SDX |
Test results
Guns & Ammo: Tested the MFMD-5.56-1.3-MDSDX-1/2X28: "performs at a level like no other suppressor I've seen." Read the review
Strategic Sciences 300 BLK MFMD
The 300 BLK MFMD is a flush-mount (0.0) model for 5/8x24 300 BLK rifles, optimized on the SIG MCX Rattler and MCX Spear LT.
Caliber: 300 BLK, subsonic and supersonic | Thread: 5/8x24 | OTB: 0.0 (flush) | Length: 4.7 in. MD, 7.75 in. with SDX | Weight: 20 oz MD, 34 oz with SDX | Material: Inconel
300 BLK shooters switch between subsonic and supersonic ammo. With bolt velocity within ±2% of baseline, you don't re-tune the gas system when you add the suppressor. With the SD on a 9 in. MCX Spear LT and subsonic ammo, it measured 128.20 dB at the shooter's ear, the lowest reading of any setup in this guide. For short barrels and night vision, we recommend the MDSDX.
| Option on our site | What it is |
|---|---|
| 0.0 MD - 5/8x24 Black | Flush, muzzle device only |
| 0.0 MDSDX - 5/8x24 Black | Flush, MD plus SDX |
Strategic Sciences 7.62 MFMD
The 7.62 MFMD fits 5/8x24 .308 and 7.62 NATO rifles in two OTB lengths: 2.4 in. (optimized on the SIG Spear) and 3.0 in. (optimized on the SIG 716 G2 and FN SCAR 20S).
Caliber: 7.62/.308 | Thread: 5/8x24 | OTB: 2.4 or 3.0 in. | Max barrel diameter: 0.82 in. | Length: 7 in. MD, 10.25 in. with SDX | Weight: 25 oz MD, 40 oz with SDX | Material: Inconel
The 3.0 MDSDX is the setup PEW Science tested. The 2.4 is a notched model (5/8X24N in the full model name).
| Option on our site | What it is |
|---|---|
| 2.4 MD - 5/8x24 Black | 2.4 in. OTB, muzzle device only |
| 2.4 MDSDX - 5/8x24 FDE | 2.4 in. OTB, MD plus SDX |
| 3.0 MDSDX - 5/8x24 FDE | 3.0 in. OTB, MD plus SDX |
Test results
PEW Science: On a 20 in. .308 bolt gun (SSS.6.230), the 3.0 with the SDX earned a Suppression Rating of 62.0 and outperformed every silencer PEW Science had tested in blast overpressure suppression.
New to suppressors? Our how to buy a suppressor guide walks you through the Form 4, fingerprints and trusts.
Strategic Sciences MFMD FAQ
What is the Strategic Sciences MFMD?
The Multi-Function Muzzle Device is a flash hider, muzzle brake and suppressor in one device that threads onto your barrel. The base unit (MD) suppresses on its own, and the optional SD and SDX modules lock onto the front for more sound and flash reduction. It's 3D printed from Inconel and was developed under a U.S. military IWTSD program.
Is the MFMD a suppressor or a muzzle device?
Both, and legally it's a suppressor. The MD suppresses on its own and is a regulated NFA item, so every MFMD, including the MD-only versions, goes on an ATF Form 4.
What do MD, MDSD, MDSDX and KIT mean?
They tell you what's in the box. MD is the muzzle device only. MDSD is the MD plus the SD (Suppressor Device) module. MDSDX is the MD plus the SDX (Suppressor Device Extended) module. KIT is the MD plus both modules, and it's a two-stamp NFA item.
What does the number in the MFMD model name mean?
It's the over-the-barrel (OTB) length in inches: how far the device reaches back over your barrel. 0.0 is a flush mount that starts at the barrel shoulder, with nothing over the barrel. A 1.3 reaches back 1.3 in., a 2.4 reaches back 2.4 in., and a 3.0 reaches back 3.0 in.
What do the N, C, LHC, HB and MG tags mean in MFMD names?
N after the thread means a notched device. C means a crown mount, for barrels without a standard shoulder. LHC means left-hand threads and a crown mount. HB after the OTB number means a heavy barrel version, and MG means a belt-fed machine gun version.
How do I know which MFMD fits my rifle?
Check three things: OTB clearance (measure from the barrel shoulder back to the handguard and leave 3/16 to 1/4 in. of space), barrel diameter (0.785 in. max for the 5.56 1.3, 0.82 in. max for the 7.62 2.4 and 3.0), and thread pitch. The MFMD Configurator matches models to rifles, or send us a picture of your rifle and we'll check it with you before you order.
What if my rifle doesn't have room for an OTB model?
Get a flush (0.0) model. We carry flush versions of the 5.56 and 300 BLK. With the SD module on, the flush 5.56 measured 134.36 to 136.86 dB at the shooter's ear with 94% to 98% less flash.
Can I add the SD or SDX module later?
The SD and SDX are only sold as part of an MD package (MDSD, MDSDX or KIT), not by themselves. If you think you'll want a module, buy the MDSD or MDSDX up front.
How quiet is the MFMD?
At the shooter's right ear, the MD with the SD module measured 134.04 to 136.86 dB on 5.56 and supersonic 300 BLK, 128.20 dB on subsonic 300 BLK, and 138.61 dB on a 16 in. 7.62. The MD alone measured 138.57 to 146.78 dB. On a .308 bolt gun with the SDX, PEW Science gave the 7.62 3.0 a Suppression Rating of 62.0.
Will the MFMD over-gas my rifle?
No. Bolt velocity stays within ±2% of the unsuppressed rifle on every tested system, with the MD alone and with the SD module. Bolt velocity is how hard the action cycles, so your gas gun runs the way it does without a suppressor.
How much recoil does the MFMD reduce?
Up to 60%, and more on some rifles. With the SD on, the rifles in this guide saw 27% to 63% less rearward recoil force. The 1.3 MD on an 11.5 in. Geissele URG-I had the largest cut, 63%.
How much does the MFMD weigh?
The 5.56 and 300 BLK MD is 20 oz (34 oz with the SDX), and the 7.62 MD is 25 oz (40 oz with the SDX). PEW Science weighed the 7.62 3.0 at 26.4 oz and its SDX at 15.3 oz. On OTB models, part of that weight sits back over the barrel instead of out front.
Is the MFMD full-auto rated?
Yes. All three of our models are full-auto rated. The MFMD is built to last as long as a barrel, and there are versions for belt-fed machine guns.
Why is the MFMD made of Inconel instead of titanium?
Inconel won't spark or burn the way titanium can, so the material is part of the MFMD's flash reduction.
Can I take the MFMD apart?
No. The MFMD is one piece and can't be disassembled. The SD and SDX modules come off the MD with a retention lever.
Does the MFMD replace my flash hider?
Yes. Take off your current muzzle device and thread the MD directly onto the barrel with the included shims and tool. No adapters. With the MD on, your rifle has a flash hider, brake and suppressor in one.
Has the MFMD been tested independently?
Yes. PEW Science tested the MFMD-7.62-3.0 with the SDX on a 20 in. .308 (report SSS.6.230), rated it 62.0, and wrote that it outperforms every silencer in its research in blast overpressure suppression, to date. Guns & Ammo also tested the 5.56 1.3 MDSDX.
Why does the MFMD cost more than most suppressors?
It replaces three devices, it's 3D printed from Inconel to a military durability standard, and each model is fitted to specific rifles.
Who makes the MFMD?
Strategic Sciences, in Salt Lake City, Utah. Its CEO, Russ Oliver, designed the MFMD. He's a former Green Beret who founded OSS, now HUXWRX. In February 2026, the MFMD completed a Phase II Government Inspection and Performance Verification.
Do I still pay for a tax stamp on an MFMD?
No. As of January 1, 2026, the federal tax on suppressors is $0. You still need an approved ATF Form 4, and we handle that paperwork in-house. The KIT is a two-stamp item, so it takes two approved Form 4s.
Ready to Buy Your Strategic Sciences MFMD?
Every Strategic Sciences suppressor purchase includes electronic filing, and your suppressor ships from our facility to your home. Need a trust or fingerprints? We handle those too, and you can upload an existing EFT file right on our site.
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