SOCOM556 RC2 and RC Suppressor Replicas

Airsoft replicas inspired by the Surefire LLC SOCOM-556 RC2 and RC suppressors with a quick-detach ratcheting mechanism and a 3-prong flash hider.

No markings, just text placeholders in 3MF files for putting your own text.

Included Additional Parts / Options

• Three-Prong Muzzle Brake
• Options for printing RC2 and the older RC version
• 3MF PrusaSlicer file where you can set your own serial number and custom text

Additional Required Parts

• 1x M2.5 x 20mm Allen Screw with Button Head Cap (as used in the real-steel version). Alternatively a Cylinder Head Cap one can be used.
• 1x Paper Clip with ⌀0.8-1.0mm wire diameter

Suppressor Versions

The version RC is for the older model SOCOM556-RC and RC2 is for the newer model SOCOM556-RC2. The only differences between the two are:

• Different suppressor caps (Crown RC and Crown RC2).
• Different markings on the body. The same 3D model is used for both (Can RC-RC2.stl), while the Can RC.3mf and Can RC2.3mf project files use it to engrave your custom markings.

Printing

• PLA
• 0.20mm layer height for most parts
• For suppressor cap / crown 0.15mm layer height
• Locking Latch 0.12mm layer height and 0.25mm nozzle
• 100% infill
• Structural rather than Speed settings

All the STL parts have their corresponding 3MF PrusaSlicer project files with the settings for Prusa MK4, and the support enforcers / blockers where required.

If you don't have a Prusa or just want to use a different slicer, instead of the 3MF files, you can use the STL files and import them into a slicer of your choice, but in that case you have to dial in your own settings. Do not use the 3MF files in slicers other than PrusaSlicer because the negative volume objects (used for the engraved text) and the modifier objects (used as support blockers) will be misinterpreted.

Nozzle

All the parts can be printed with a 0.40mm nozzle, but the Locking Latch will function better when printed with a 0.25mm nozzle.

Material

PLA is highly recommended, as it does not shrink. I used eSUN ePLA Matte that is quite sturdy and prints beautifully.

Tolerances and Calibration

The tolerances are built into the model, but since there are some moving parts that need to be properly fitted (not too tight and not too loose), you should use a quality filament with a consistent diameter, and have your printer properly calibrated.

If you find the moving parts too tight, you can lower the extrusion a little (if using PLA), or increase the XY scale by a few percent (if you are using ASA or some other material prone to warping).

If you use PrusaSlicer, for checking the settings you can print the Calibration.3mf model and check the following:

1. Perimeter thickness of the printed box should be around 0.42mm. Even though the setting say 0.45mm, the actual extrusion should be around 0.42mm - at least for my printer, this is the value where I get the best results. Use Extrusion multiplier to adjust the thickness between that range. Lower values give you a better engraving definition, but inferior layer adhesion, while higher values result in better layer adhesion, but lower quality of the engravings, and the fit can become too tight. Do not proceed to the next step before having completed this one!
2. Verify that the outer and inner diameters of the two rings fall between the values specified below. If not, adjust the X and Y scale factors to achieve the target range (Z should remain unchanged).
   • Bigger Ring Outer diameter 35.8-36.0 mm; Inner diameter 31.8-32.0mm
   • Smaller Ring Outer diameter 31.8-32.0 mm; Inner diameter 22.5-22.6mm
3. You should be able to force the smaller ring into the bigger one using just your fingers. They should click very snugly and once in they should not fall apart. If not, go to step 1 and adjust the Extrusion multiplier.

Custom Text and Markings

The model of the suppressor body (Can RC-RC2.stl) has no brand markings. The corresponding Can RC.3mf and Can RC2.3mf are PrusaSlicer project files using that STL, that have placeholders where you can set your own custom text, a dummy serial number, and whatever makes you tick. It is entirely up to you, and I bear no responsibility for your choices.

Assembly

Pictures P1 through P10 show the details of the process.

1) Print all the parts and carefully remove the supports. Recommended layer height for suppressor caps is 0.15mm

2) Insert the Adapter into the body (Can) aligning the groove with the guide tooth. Once you verify that it fits, take it out, apply a small amount of super-glue and insert it back in.

3) Mount the suppressor cap (Crown) to the top.

4) Straighten a paper-clip and cut it to the length of 98 mm.

5) Bend the paper-clip wire it as shown on the photo to form a spring for the locking latch. You can use the bigger calibration ring as a template.

6) Insert the wire into the groove on the inner side of the Locking Ring and insert the hooked end into the 1mm hole to hold it in place. Cut off the excess if any.

7) Ensure that the Flash Hider can freely and fully insert in and out the adapter body, paying attention to the position of the locator tooth. Work it out a few times.

8) To prepare the Locking Latch you can use one of the two options:

• Option A (the easier one) is to widen the hole on the Locking Latch so it can freely turn around the bolt without wobbling.
• Option B (used in some metal replicas) is to strip down the last 9 mm of the threads down to the thickness of 2.1 mm. Ensure that the Locking Latch can freely turn around the bolt without wobbling.

9) With the flash hider fully inserted, tighten the Locking Ring all the way. Work it out a few times until the ring starts turning smoothly. Ensure that the spring is not grinding against the threads!

10) With the flash hider still in, untighten the locking ring just until the locking teeth on the adapter are no longer visible through the cutout on the ring. Insert the Locking Latch and keep it in place with your thumb until you drive the bolt all the way through.

The locking latch should be smoothly returned by the spring to its position. If it does not, file a bit the inside of the upper lip of the locking ring where the latch is sitting.

When you tighten the ring, you should hear the lock clicking. To untighten it, first press the lock and turn the ring half a turn while holding the lock pressed. Turning the ring without having the lock pressed will wear out the teeth. Also if your printer is not tuned properly, it might not catch the teeth, or catch them even when depressed. Since that is more of a cosmetic than a functional part, you should not worry to much about it. When you tighten the locking ring, it will hold great even without the lock catching the teeth.

The Flash Hider should be mounted onto the replica (CCW thread) so the locator tooth is facing downwards. Use the enclosed "M4 Flash Hider Timing Washers.3mf" to print a set of washers of thicknesses between 0.2mm and 0.9mm (in steps of 0.1mm) to adjust the timing. You can optionally use a headless M3 headless Allen bolt to fix the flash hider in place. Do not overtighten!

While tightening the flash hider, be careful not to squeeze the the prongs, or they will break. You can use this wrench.

Preventing Baffle Strikes

To avoid BBs from hitting the baffles and the exit cap, after having assembled and installed the suppressor for the first time, take out the upper receiver and look through the barrel hole from the BB's point of view, to verify that the mouth of the suppressor is not visible, i.e. is not on the way of BBs.

If you can see the border of the exit hole through the barrel, especially when the locking ring is tightened, and/or the suppressor slightly wobbles when placed on the flash hider, reprint the flash hider and scale it up in the X and Y axis by 0.1mm, to prevent the wobble. Z-axis has to remain unchanged!

Increase further up slightly if it still wobbles.

BAFFLES

IMPORTANT: Check the laws of your country to verify the legality of suppressing the sound of airsoft replicas. In cases where it is not allowed, you should not be using the baffles!

Sponge Baffles

To suppress the sound of a replica, you can either cut and place an old propulsion spring wrapped in a sponge inside the suppressor, or you can print the baffles. I made a tutorial for making 3D printed spongy suppressor baffles.

"Whisper" Baffles

There is a model of the stackable Whisper Baffles compatible with this and all suppressor replicas with an inner diameter of 32mm.

POST-PROCESSING

I used the eSUN ePLA Matte filament, which has a very consistent thickness and beautifully hides layer lines, but you can optionally do the following:

• Smooth the holes on the cage using a 4mm drill
• Sand the printed parts to hide the layers
• Spray the model with some Armamat or similar matte spray.