Taking Elite Force’s 4CRS to the Next Level
There are so many great-performing AEGs coming out on the market each week from reputable manufacturers that it is not as common as it used to be to fully deck-out and build-up a gun. This works out great for any level player but although many new guns not only perform well, but look the part right out of the box, the question remains; how do you really stand apart in the crowd? Well, to be feared on field and send big men like Tom “The Tominator” seeking shelter and crying for his mama, you go custom! So we are starting Airsoft Insider off with an Elite Force M4-based build and we’re going to show you how to change its attitude inside and out.
AT A GLANCE
WHO MAKES IT: Elite Force (VFC-based gun)
GUN NAME: “Troy Force”
CLASS: Custom AEG
TYPE: M4 Variant
WHO IT’S FOR: Mid-High Level Player
HOW MUCH: If you have to ask it’s too much; but seriously, approximately $1,544.99
FPS: 360 fps w/.20g, 325 fps w/.25
SHOOTER’S OPINION: As the person who assembled this gun, of course I’d like to say that it is the best; however, I think a longer rail could have made the gun’s ergonomics a better match for my personal preference. The Battle Ax stock seems to have a little wiggle to it but I’d choose it again if someone called a redo. While the performance of this gun isn’t pushing the limits of AEGs, the aim was to build a solid performing gun that would be field-able at my local fields and perform well. Mission accomplished!
A. RIS (Rail Integrated System)
Madbull Free Float 7-inch Troy TRX Extreme Battle Rail, 272052: $116.99
Madbull Battle Ax (black), TroyBAS: $105.00
G&P Troy midcap (black), SOG-BM-M: $59.00 (five-piece box set)
Madbull Troy Battle Ax (black), MB-TBGC-BK: $31.00
E. SLING MOUNT
Magpul RSA, MAG502: $26.49
Inforce WML Tactical Weaponlight, INF-WML-B-W-M: $149.99
Eotech XPS2-0 Holographic Weapon Sight, XPS2-0: $499.99
H. RAIL COVERS
Magpul XTM Stop Kit, MAG511-BLK: $24.95
OMGTAC TBO Tactical Bottle Opener, AC-UP-OMG-TBO: $15.99
G&P M120 High-Speed Motor, MO-GP561: $40.00
SHS 13:1 ratio, 32511: $24.99
Hurricane AEG Gun Metal Shim Set, HUR-1769_HE-07-02: $6.00
4. PISTON & HEAD:
G&P White Piston, PT-SP001: $19.99
Modify M110, 146330: $16.99
6. INNER BARREL:
Airsplat A5 Tactical 6.02x300mm right bore
7. HOP-UP UNIT:
Madbull 3-in-1, MB-HOPUNIT: $30.00
VFC V2 Gearbox
8mm Bushings (stock)
Full Metal (stock)
VFC V2 Rear Wire (stock)
CYLINDER & HEAD:
Metal Cylinder and Polycarbonate Head
M4 Type w/O-ring
Metal Ball Bearing-Type
• P2 screwdriver
• P1 screwdriver
• Flat-head screwdriver
• 1.5mm Allen driver
• 2mm Allen driver
• 2.5mm Allen driver
• 3mm Allen driver
• Pinion gear puller
• Cut-off wheel for Dremel
• Gear grease
• Silicone oil
• Blue thread-locker
• Armorer’s wrench
• Heat gun
• Small punch
Usually when I build a gun, I like to stick with a theme or line of parts that will give the weapon a cohesive look when it’s finally assembled. On this project, I decided to run with Madbull external parts because Madbull has global licensing on a wide variety of products and I am a huge fan. As for the internals, I wanted to try some trusty standbys that I know will do the job and I was hoping to experiment with some new ones as well. With that said, a book could be written on this build but I only have so many pages to go over the details. I’ll do my best to give you as much information as possible to help you breakdown your project gun and build it up with similar success.
THE BUILD OUT
Typically on a big build I start with the internals and work my way out. The gears are the first to go in and this time I selected a set of 13:1 ratio SHS gears. The low price and good quality made this an easy choice; I was also looking for a high rate of fire in this gun. I’m not going to get into shimming because that could possibly turn this already long article into a book. What I will say is that it is important to eliminate side-to-side movement in the gears while making sure that they are free to cycle quickly. You want to be sure the teeth can properly grip one another with enough surface space so they do not strip. It’s best to have the bevel gear lower to the pinion of the motor and I like to have the sector gear a little loose.
On to the piston; using the P2 again, I put it into the rear of the piston and held the aluminum piston head with the other hand and removed the screw. Once it was out, I removed the screw and its metal sleeve as well as the spacer. Using the white G&P piston, I then placed the spacer back in followed by the sleeve and screw. With these poking out of the top I added a drop of blue thread-lock. Then I placed the white spacer included with the piston onto the front with the flared end in the piston. That was followed by the aluminum piston head. I threaded them on tightly and wiped up any mess. I chose the white piston for the spacer and the manufacturer had already removed the second tooth on the piston; resulting in a gun with a higher rate of fire.
Next, I added few drops of silicone oil on the O-ring of the piston head and slid it back and forth within the cylinder. I removed the nozzle from the cylinder head and cleaned it off. Then I added a drop of lube to keep a good seal with the small O-ring inside. The next step was to slide the nozzle back on and place the tappet plate back in the groove on the nozzle. Then I put this assembly back into the gearbox. Be sure to reattach the spring for the tappet onto the post in the gearbox and verify that the piston is sitting in the grooves on both sides of the gearbox.
Now put some grease in those grooves on both sides of the box and on the side rails of the piston. You only need a small dab. I also put a thin coating on the gears, being sure not to disturb the carefully placed shims.
Gently place the anti-reversal latch back in place under the bevel gear. Make sure the spring is under it as well and that it pushes the latch toward the gear.
Once it’s all set into position, slide the new spring back into place. For this build I went with a M110 spring. This will allow for a higher rate of fire but lower fps. Since I wasn’t planning on building a sniper or DMR I’m perfectly fine with this. Now take the driver used to disassemble the gearbox and slide it into the spring guide and put the two parts in the back of the spring. Hold the gearbox in your right hand against your workspace and using your left hand, pick up and slide the spring and spring guide into place. Once installed, continue to hold the spring in by pushing down on the driver and with your right hand, place the top half of the gearbox shell back on. Be sure all the shafts for the gears and the piston are set in place and there is no gap around the box.
Continue to hold the box together and place the eight screws back into their respective positions. Then replace the flat-head screw onto the rear. Give the piston a quick check by sliding a small tool into the nozzle and pushing to see that it moves. Keep in mind that you are pushing against a slightly-compressed sling. Remove the tool and press on the nozzle with a finger, making sure it moves in and pops back under the power of spring. Lastly, put the bolt-catch arm back onto the exterior of the gearbox. Confirm that the spring is keeping the metal plate up.
Place the gearbox back into the lower receiver and verify that the selector switch is between safe and semi. Tilt the front of the box down and slide it back and in. It may require a light tap on the top rear portion to coax it into place.
Replace the floral pin from earlier and tap it with the plastic end of a screwdriver until it is flush. This will prevent damaging the body with a metal hammer or other solid object.
Now put the mag release back in. This is done by first sliding the arm back into place and then installing the spring in on the other side followed by the button itself. You should get at least one full turn of the button before it is hindered by the body. Once this happens, push the button into the body and turn the arm part of the release in a clockwise direction until you can no longer make a full turn and it slides into place.
Put the bolt release button back into place by sliding the arm under the gearbox into the slot on the bolt-release plate. Tap the pin back into place.
The next step is to place the new grip on the gun. I went with the Madbull Troy Battle Ax grip. Its only downside is that it requires a medium motor. But fear not, you can buy a long motor of your choosing and shorten it. I went with a G&P M120 high-speed motor to keep with the higher ROF gun I’m trying to create. While I am not aiming to push this gun over the limit, I’d like something that performs a bit better than stock.
First step in shortening the motor is to remove the pinion head from the motor. Use a pinion puller and pop it off. Next, take the spring and sleeve off the shaft of the motor. Use a spare medium motor and measure the length from the rear of the motor on the furthest point to the top of the pinion. Write down this measurement and transfer this onto your motor of choice. You will be removing the extra length from the pinion side of the motor. Be sure to wear safety glasses and use your Dremel tool to cut the excess off. Leave as level and neat of a cut as humanly possible. Now you are ready to press a pinion back onto the shaft using your pinion puller.
Take your AEG’s grip and place the two small 2mm hex screws into the base, affixing it to your gearbox. Be sure to run the red wire along the top of the grip around back to the rear so it comes up next to the black wire. Now attach the two wires to the motor; first the black and then the red wire which will go over the black. You may need to shorten the wires by cutting some of the excess and butt-solder the wire back together. Now put the base plate on and snug the screws. At this point, I normally test the gun to make sure it works. Plug a battery into the gun and give it a quick burst on full-auto and a couple of shots on semi. Once you verify that it is working properly, you are safe to move on. If not, then you will have to go back, diagnose and fix whatever issue occurred.
Place your sling plate back onto the rifle and follow it with the stock tube. Be sure the wires running through the stock tube are pulled taught. Slide the screw and plate down the tube and snug it up using you P2 again. Don’t pinch the wires. I also removed the stock Tamiya connectors and soldered on a Deans plug. For info on this, see our How-To Connector Swap article in this issue.
Once the Deans is attached, slide the new Madbull Troy Battle Ax stock onto the stock tube by placing two fingers in the rear and pulling the release lever down as far as possible. This stock was chosen because of its new, but basic and sleek look as well as the Troy branding to match the other accessories. There are also three push QD sling swivel points and a very large battery storage compartment. Madbull even makes a battery just for this. Again, give the gun a quick test to confirm that no parts were damaged and the wires were not pinched before moving on. Your lower is now complete but don’t get too happy because now it’s time for the upper!
Take the cowboy hat back off and get to work! Let’s start with our new barrel and hop-up. We selected the Madbull 3-in-1 hop-up. I often choose this hop-up because it can be fine-tuned. Luckily, they include instructions for the install but it’s pretty simple. There are three O-rings that need to be placed on the hop-up, two on the rear to help seal the unit and keep the adjusting wheel in place and one to keep the BBs in the unit located on the bottom. Just slide them into position. Next, put the bucking over the barrel. You’ll need to align the notch with the barrel and slide it to the end. Add a drop or two of pure silicone oil onto the bucking and slide it into the hop-up unit. Look through the unit and barrel to see that the bucking is set in place and it’s perfectly round. If it isn’t, it can cause air leaks and poor hop-up performance. Now slide the small nub into the top of the hop-up unit and place the adjustment arm over the top. Be sure the nub is sitting in the notch on the arm. Now slide the pin through the small hole in the side of the hop-up unit and through the adjustment arm. Place the small retaining clip on the small shaft side of the pin and finally, place the adjustment ring onto the rear of the hop-up and verify that the extended-back portion slides into the groove on the wheel. Turn the hop-up to its lowest point of adjustment and now it’s done.
Assembling the front section of this gun is pretty easy. The seven-inch Troy TRX extreme rail was chosen to stay with the Troy theme and to get modular rails onto the gun so they can be placed at user preference. Take the outer barrel and upper receiver and slide the two together. Next, take the barrel nut and put a dab of grease on the threads and begin to thread it onto the receiver. This will help it get on a little easier and will allow it to come off when needed. You will get to a point at which you will need your armorer’s wrench to snug it up. Be sure the teeth on the ring line up with the hole for the gas tube. Once it’s on and snug; slide the rail onto the nut to confirm that the top rail fits to the rail on the upper receiver and adjust accordingly.
Take the rail back off and put the rail sections on as desired. It’s much easier to do this while the rail is off of the gun. There is a plate that needs to slide into the inside of the rail to hold the screws for the actual rail section. Place the rails in the positions most comfortable for you. Hold the plate to the inside, place the rail section on the outside then put at dab of blue thread-lock onto the screw and secure the rail section. Once you have the desired number of sections in the proper places, slide the rail back onto the gun.
Using a 3mm Allen driver and some blue thread-lock, install the final two screws.
Now take your front sight with the gas tube and gently slide it into place. Replace the two pins and 1.5mm grub screw in the bottom. Reattach the flash hider and the majority of the gun is complete.
Now it’s time to decorate! I put the rear sight back onto the rifle.
I then added an XPS Eotech. Yes, I went big and put the real thing on there because I could. After that I attached the Inforce light. This was chosen for its new styling and great ergonomics as well as the dual bright white light and IR function.
On the lower rail, I installed the Magpul Xtm Hand Stop Kit. I couldn’t fit the entire thing on the short lower rail so I only added the pieces I desired. It seems like I just cannot build a gun these days without using at least one Magpul accessory.
Speaking of Magpul, I put on an RSA ,or railed sling adapter, for a front sling point.
Last but not least, on my only free rail, I put on my OMG TAC TBO, also known as the Tactical bottle opener.
Slide the hop-up and barrel back into the upper and place the upper back onto the gun.
Now that the hours were well spent to create Project Troy Force, it was time to test it. I loaded the midcaps up with some Elite Force .20g BBs and an 8.4V 1600mAh NiMH battery. Then I took it outside and ran five mid-caps through it and was more than happy with the performance as the internals broke in. After some fine-tuning with the hop-up unit, it was time to Chrono the gun. With .20g BBs, the gun clocked in at about 360 fps. Next, I popped in a mag with .25g BBs, put it back on the Chrono and it averaged 325 fps. Not bad with a relatively soft spring and no modification to the piston head nozzle and other air sealing components. Now it was time to check the rate of fire (ROF) on full-auto. Using the 8.4V again, I set up my Chrono and gave a good long squeeze on full-auto. The Chrono read 20.64 RPS (rounds per second). I removed the 8.4V and installed the 9.6V 1600mAh NiMH battery. Again giving it a good pull, the Chrono came back with 26.25 RPS; a 6 RPS increase from the last. Finally it was time for the 11.1V 1200mAh 20C Intellect battery. I held it wide open and emptied the mag in a few seconds. The Chrono read 34.51 RPS. These are some excellent results and worth the time, effort and money spent on the build. Now it was time for some plinking. I took the gun out on my local field and the range accuracy and rate of fire were exactly what I was looking for; actually more than what I was looking for! I had a very quick trigger response with no double tapping and the mid-caps were able to keep up perfectly when shooting in full-auto. Project Troy force was a success!
ROF- 8.4V- 20.64 RPS; 9.6V- 26.25 RPS; 11.1V- 34.51 RPS
CHRONO- .20g- 360fps; .25g- 325fps
THE LAST WORD
This was a simple build with a great performance payoff! The Elite Force 4CRS proved to be a great base platform for the project and the Madbull additions gave it a very cool custom look. Bulking up the internals should hold up to the rapid fire and I’m sure it will be a long time before I encounter any issues that would require a rebuild. So the question is; should you replicate this build? This turned out to be a great build from both the quality and performance aspects. I have no problem suggesting you take cues from this build to custom-build your own project; that is if the cash flow permits.
Airsplat, airsplat.com, 626-539-3900
Elite Force, eliteforceguns.com, 479-646-4210
EoTech, eotech-inc.com, 734-741-8868
Evike, evike.com, 626-286-0360
Ground Zero Airsoft, groundzeroairsoftusa.com, 203-879-7766
Inforce, inforce-mil.com, 401-294-2030
OMG Tac, omgtac.com
Words: Jimmy Beckett
Photos: Walter Sidas