Sunday 20 December 2015

Review: ForceCore FC-108

Time for a gun review!

In the following I'll be looking at an M4 variant, the FC-108, from the fairly new Chinese ForceCore AEG line. ForceCore is not a manufacturer, but a brand. The original manufacturer is, sadly, a mystery. The guns are nevertheless rather affordably priced and fairly high in quality.

The review gun was generously supplied by Gunfire.pl, who at the time of writing are the only ones selling the brand. This model currently retails for about 165 EUR. You can get one here.


Unboxing




The gun comes packed in a fairly unassuming brown cardboard box with only the company logo sticker on top and a small contents sticker on the back. Personally I've never been that big on the whole "out of the box experience" or whatever you want to call it. For me, the box is there to keep what's inside safe for transport, and that's it. If you can cut down costs with simple packaging and reflect that on the end user price, I'm all for it.




Popping the lid you will find the gun and peripherals packed in a cut-to-shape foam insert covered by a sheet of foam. Pretty standard practice and works nicely.



The gun is partnered with a 300 rd metal hicap magazine, an 8.4V/1200mAH NiMh battery and charger, a dummy PEQ box and flip-up front and rear sights.

First impressions

Anyone familiar with the real steel AR design will obviously notice that the gun is lacking a buffer tube essential to the functioning of the real rifle. You could argue this is a gas piston driven AR and be done with it, or switch the end cap to a buffer tube of your choosing, but in the end this is not the most likely choice for a milsim environment anyway. This might be a plus or a minus depending on how realistic you prefer your replicas.

Despite its small size, the gun feels nice and sturdy in your hand. The metal body has a good looking finish all around, and apart from the very slight sideways wobble of the upper receiver, there is little to complain about. The sights are all metal and flip up and down with a reaffirming snap. The rear sight has elevation and windage adjustment, the front sight has an elevation screw. There is one negative to the sights, though. As the rear sight is a peep style, you need to hold your face rather close to it in order to get a sight picture. Without a stock this becomes a somewhat awkward exercise and the sights, while very nice looking, become fairly useless.

To get inside the battery box, you need to undo and then redo three small screws at the front of the box, but at least the battery will stay in place once in. The pistol grip (Storm grip style) fits my hand far better than the more typical, thinner version used in most M4 replicas, and the whole package has good heft to it, weighing in at 2780g.

Performance

After fully charging the battery, I chronoed the gun with a UFC Pro chronograph. If you're used to LiPo batteries and neodymium torque motors, the trigger response will feel a bit sloppy, but it's completely typical with other NiMh battery powered ferrite motor guns.

With 0.28g Rockets Platinum Bio BBs I got a muzzle energy of around 1.34J and 13 rounds per second straight out of the box. In my opinion this was a bit too hot considering the gun's size. I'd most likely use it in a CQB environment, and for that the energy is too much to use safely. I would opt for a CQB legal spring which, if you don't want to tech yourself, you can have Gunfire install for free when you order. After a period of shooting (around 300 rds), the spring had settled down some and the gun chronoed a nice 1J with 0.28g BBs or slightly under that with 0.20g BBs.

The gun was surprisingly accurate, and from a distance of ten metres I could hit an area the size of my palm when shooting from a rest with carefully aimed semi-auto shots.

Externals

The upper and lower receiver, the free float RIS rails, the muzzle device, trigger guard, trigger, sights, sling plate and end cap are all made of metal and and have a matte black powder coat. 


The left hand side of the receiver has painted markings with a skeleton frog logo and "Navy Seal Team" "Force Core" and "Force Core Industries" texts along with what looks like a serial number and the fire selector markings Safe, Semi and Auto. Whether or not all guns are individually numbered, I don't know, but I assume they are not.  The right hand side is completely blank apart from the fire selector markings identical to the left side.



Nice touches that make the ForceCore series stand out are the previously mentioned pistol grip and the angled and shaped trigger guard.



The muzzle device is closing in on the definition of epic, and its conical shape at the end of the barrel will most likely make this thing even louder than it might otherwise be. That's a positive in my book, just to make things clear. 



The muzzle device screws off like any other to reveal 14 mm anticlockwise threading beneath it, so you can easily install a different muzzle device or suppressor if you so please.



Pulling back the charging handle opens the dust cover to reveal a fake bolt and the hop up unit adjustment wheel. This is where I found the quality assurance had been a bit lacking in the factory, as the fake bolt was covered in metal dust, the source of which I could not readily find.


The end cap screws off by hand or, if need be, with an allen wrench via the hex bolt inside the cap.



Once off, the end cap reveals a cut down buffer tube shaft. This is a cool little feature of craftsmanship, as the shaft is obviously cut down by hand. Even though the shaft is short, you can still securely mount a buffer tube on it without problems. The sling plate is made of steel, which is very good considering there isn't a front sling mount, so this is the only place for your gun to hang from. No worries that this will break off anytime soon. 



The free float RIS rail at the front is secured in place via two small hex head grub screws and twists off easily once the screws are loosened.



The pistol grip bottom plate is a thick piece of metal with a hefty motor height adjustment screw. It attaches with reassuringly long screws, which will make sure it stays where you put it.

Internals



The disassembly of this M4 is much like any other, but a word of warning is in order. The front pin is secured with a small spring loaded pin inside the receiver that pushes into a notch on the end of the pin. 



The idea is that you don't pull out the front pin fully, but stop at where the spring pin hits a notch and locks the front pin in place. The problem is, it is very easy to pull the front pin much further. The spring is not very strong, and especially if you twist the front pin so that the spring pin does not meet up with the notch, there nothing stopping you from taking the whole front pin out. The spring will then shoot the small pin out of the hole, and you will end up losing it especially in field conditions. 

It's a nice idea, but doesn't quite work. If there was a groove machined between the two notches, it would stop the pin from twisting and make it less likely for you to lose the pin. The smaller pin could also be secured in one way or another so it will not exit the hole. At least it is easy to create a replacement should you lose the smaller pin.



The rear body pin is secured with a split type spring pin, and makes sure the rear pin does not get lost. This design works much better than the front pin one.



The motor is an unmarked grey ferrite deal with a D shaped pinion secured with a screw. Nothing fancy, but it gets the job done, especially with a less heavy spring like this one.



Once you screw off the RIS handguard, you are left with a barrel nut and the wires terminating in a -Tamiya connector. As you might note, the gun does not have a fuse anywhere, which is atypical. I assume it has been left out due to the lack of space. A bigger problem for me was that there also were no connectors to split the wires, so in order to disassemble the gun further the barrel nut and barrel would have to come off. The barrel nut on mine was screwed on so tight, however, that once it did not move with sliding tongs, I dared not try to twist it any more lest I crack the receiver. I opted to simply cut the wires and attach small flat connectors to enable the pass-through.




The hop up unit was surprisingly cast metal and not plastic as they often are. Otherwise it's as typical an M4 hop up unit as you can get. The inner barrel is brass with a soft black bucking.




The gearbox shell is made of metal painted black and does not have strengthening cuts at the front of the cylinder. It comes with 8 mm ball bearings directly from the factory. A welcome change from the typically plastic bushings you see in Chinese guns. My gearbox was missing one screw, another lapse in quality assurance on this otherwise very promising package. All the other screws were well tightened at least. The shimming was not too bad, either, even though the bevel gear had a bit more free play (around 0.3 or 0.4 mm) than I'd like.




Inside the gearbox we find unmarked 18:1 steel gears, a steel antireversal latch and not a whole lot of grease. What little grease there is, is the sticky and gunky brownish orange stuff you usually find in these less expensive guns. The sector gear has an interesting enlarged tappet post, which in effect works as a small delayer chip. The cylinder looks like steel, but is not magnetic.

The spring guide is steel, but does not come with bearings or washers. There also are no bearings or washers on the inside of the piston, so the spring will twist a bit as it is wound back. A couple of simple washers and some grease would go a long way in reacting to the twisting. The spring itself is linear and rated around M100 judging from the chrono readings.




Shimming of the gears in relation to each other is not at all bad, though obviously not as close as you can get with time and effort. For a stock gun, though, this is nicely done.




The piston is curiously a half-toothed one. The body is plastic, and rack is steel with the second tooth is removed as stock. Mine came with some tooling marks on the piston body near the tip, but they do not affect performance in any way.




The nozzle is brass and comes with an o-ring, which is a very pleasant surprise when compared to the non-o-ringed plastic ones which typically come with guns in this price range.




Cylinder head is plastic with a single o-ring and a brass tube. All in all, the airseal between the main pneumatic components was extremely good when tested.




The angle of engagement (AOE), though hard to see from the picture, was not entirely perfect, but much closer to it than what you typically see in stock guns. With the stock components, I'd assume this gun to last a very long time without problems.

Magazine compatibility test

As I had some different makes of magazines lying around, I got the idea of testing them on the gun to see how they fit. I also enlarged the selection by borrowing some extra magazines from friends as well, and the results are as follows: 


Make & model Fit Feeding Release
Dboys metal lowcap Sits in nice and snug, occasional slight wiggle required to mate the mag with hop-up unit Feeds without issues Falls out when magazine release is pushed
Dboys metal VN style midcap Sits in nice and snug, seats without any wiggles, best fit of the bunch Feeds without issues Falls out when magazine release is pushed
Dboys metal midcap Sits in nice and snug Feeds without issues Falls out when magazine release is pushed
King Arms plastic SIG midcap Sits in nicely but requires a bit of wiggle to seat Feeds without issues Hangs when magazine release is pushed, requires a small tug to get out
Ares Amoeba plastic midcap Fits inside the magwell but will not seat N/A N/A
Dytac Invader plastic midcap Just barely fits inside the magwell and seats when pushed with considerable force Fees without issues Hangs when magazine release is pushed, requires considerable pulling to get out
MAG plastic midcap Sits in nicely but requires a bit of wiggle to seat Feeds without issues Hangs when magazine release is pushed, requires a small tug to get out

Final thoughts

Considering the price range, the FC-108 is a definite winner. With parts you typically have to pay extra and install yourself coming as stock, the quality of the externals and performance straight out of the box being very nice, this is a very good choice for a CQB gun that can be run a long time without any modifications. A few quality assurance issues did crop up during the review, but none of them had an actual impact on the actual performance of the gun. I'm definitely giving this two thumbs up! You can get yours here.




If you have the possibility, I also suggest swapping the battery for a 7.4V LiPo and the connectors to Deans to up the performance some. You may also want to open the gearbox to apply more grease to the moving parts. Other than that, there is no definite need to update anything if you don't want to. If you do, however, this is a great basis for tuning a short, personal looking gun to match your personal specifications.

Pros and cons - A TL;DR

Pros

  • Affordable
  • Very nice internals (o-ringed brass nozzle, 8mm ball bearings, steel gears)
  • Large storm style pistol grip
  • Personality with trigger guard and muzzle device designs
  • No way to lose rear pin
  • Fairly sturdy and well finished externals

Cons

  • Sights not very usable without a stock
  • Connectors can't be moved inside the handguard due to lack of space
  • No bearings on spring guide or piston
  • Grease on internals is the gunky sort and there is fairly little of it

Suomenkielinen tiivistelmä

ForceCore on uusi kiinalainen sähköasebrändi, jota tällä hetkellä myy ainoastaan puolalainen Gunfire.pl, joka myös toimitti tämän arvostelukappaleen. Kyseinen ase on mallia FC-108 ja sen myyntihinta kirjoitushetkellä on noin 165 EUR. Ase löytyy kaupan sivuilta täältä.

Kyseessä on erittäin lyhyt M4-variantti, jossa on lyhyt free float RIS-kiskokädensija ja tukkiputken tilalla kierrettävä perätulppa. Akku (8,4 V NiMh) sijaitsee mukana tulevassa AN/PEQ-kotelo-dummyssa. Aseen mukana toimitetaan yllä mainittujen lisäksi metallikuorinen hicap-lipas (300 kuulaa) sekä kiskokiinnitteiset metalliset flip-up-tähtäimet. Painoa koko paketilla on vakuuttava 2780 g.

Ulkoisesti ase on varsin siisti, metallirungon valu on kiinalaiseksi oikein kelvollista, vaikka ylä- ja alarungon välillä onkin pientä heiluntaa. Kaikki rungon merkinnät on maalattu kaivertamisen sijaan. Pistoolikahva on perinteistä M4-kahvaa paksumpi, mikä ainakin omaan käteen tuntuu paljon perinteistä paremmalta. Liipasinkaari on tavallisen suoran palikan sijaan muotoiltu kaarevaksi, mikä tuo aseelle omanlaistaan luonnetta.

Akkuliittimet ovat perinteeksi muodostuneet mini-Tamiyat, jotka mahtuvat liikkumaan kädensijan sisällä valitettavan huonosti. Johdoissa ei ole myöskään jatkoliittimiä, joten ainoa tapa purkaa ase on joko irrottaa koko kädensija ja ulkopiippu tai katkaista johdot ja laittaa liittimet itse.

Sisäosat olivat aseen varsinainen yllättäjä. Rataslaatikossa on vakioaseeksi varsin hyvin shimmatut teräsrattaat 8 mm kuulalaakereilla, messinkinen o-renkaalla varustettu suutin ja metallihampainen mäntä. Ainoastaan rasvassa oli säästelty ja sekin, mitä sisältä löytyi, oli paksua keltaruskeaa möhnää. Rasvan puute pois lukien näillä sisuksilla pelaisi mitä luultavimmin ongelmitta pitkänkin aikaa.

Suoraan laatikosta ase kronotti hieman ylimitoitetun 1,34 Joulea, eli reilusti yli sisäpelirajojen. Muutaman kymmenen laukauksen jälkeen jousi ilmeisesti hieman asettui ja krono näytti inhimillisempiä 1 Joulen lukemia, joten ase menisi mainiosti sisäpelikäytössä.

Ainoat muutokset, joita itse tekisin heti alkuun, olisi akun vaihto 7,4-volttiseen LiPoon ja pystykahvan ja punapistetähtäimen käyttö, sillä vakiona tulevat flip-up-tähtäimet ovat melko yhdentekevät tähtäyskäytössä.

Kaiken kaikkiaan kyseessä on eritoten hintaansa nähden erittäin kelpo paketti, joka on suoraan laatikosta varsin toimiva ja palvelee käyttäjäänsä varmasti pitkään täysin vakiona. Myös virityspohjaksi tässä on oikein mainiot edellytykset. Ehdoton suositus varsinkin vähän vähemmän tyypillistä, mutta M4-standardia mukailevaa sisäpeliasetta hakevalle.

Saturday 5 December 2015

Magpul Mishmash

My latest build is another M4. As much as I've grown to loathe the v2 gearbox, I'm pretty happy with how this one turned out in the end.


The whole thing started out as an externals build. Ever since I got the G&G M4, I had been on the market for a metal M4 receiver. The plastic one simply didn't do it for me. Before I got it, though, I had been buying second hand externals over time to spice up the appearance of the G&G. Once I finally happened upon a fairly cheap used upper and lower receiver set that also came with a gearbox and motor, I had enough parts to build a whole new gun. So I stripped the G&G and began work on the new gun.

The Magpul handguard (though actually an ACM copy, I believe) was very nice to hold, but came with one or two problems. Namely that one, it was too thick to fit directly inside the delta ring of my current upper receiver and two, it was longer than where the front sight sat on the barrell I was using.



The first issue was rather quickly solved with a bit of filing. I used some vinyl tape to protect the parts I didn't want to scratch.



The second issue took a bit more work. The original front sight had to go.



I didn't want to get a whole new front sight, so I simply lopped of the top part with a saw and began to file down the rough edges to make it fit inside the handguard.



As usual, I got a bit carried away with the shiny metal surface and in the end I filed the whole gas block down to a shiny, smooth piece. I also removed the sling mount and bayonet lug as they would not be needed inside the handguard.



And in the end, like a carefully crafted scale model plane cockpit, it's hardly visible once done, only bringing joy to the original builder.

One further problem reared its head, and it was the fact that the handguard would not actually now stay in one piece as the retaining ring did not have the gas block in front of it.



I settled this in a simple manner and screwed on a nice looking suppressor that pressed the ring down and locked the handguard in place. This might not be the correct way to do it, but if it works, what the hell.

I also wanted to replace the trigger guard and pistol grip. My hand is not designed to work with the original AR series pistol grip. The finger shelf simply seems to sit in a completely wrong place. I opted for a nice looking Dytac HK416 style pistol grip. Obviously it would not fit directly onto the lower, so I had to file the upper edges of it down by approximately one millimetre all around, and also slim down the lip protruding onto the underside of the trigger guard.



The rotary tool slipped a couple of times, but always in the direction that does not show, so all was well.

The trigger guard I got was an FMA one in olive drab (it was the only colour on sale). Luckily the material was slightly porous, so a couple of layers of spray paint did the job splendidly.



Once dry, the trigger guard fit into place without any modifications, which seemed almost unusual at this point.

The last bit to add was a Magpul PTS (authentic this time) CTR stock. The stock locking spring on it is from another world when compared to cheap airsoft stocks and it took some effort to push down far enough for the stock to slide onto the buffer tube, but otherwise it was such an undramatic event I didn't even take pictures.

One final piece to fix was the missing cover on the right hand side of the lower receiver. I bought some Dytac cover plates only to discover they're made to a wildly different specification than my lower used.



As is obvious, the inner diameter of the hole is much bigger than the raised portion on the cover plate. I opted to take the quick and mostly painless road of cyanoacrylate.



At least the outer diameter and height of the cover was similar to the detent in the receiver, so once the glue dried, everything was breezy. Super glue on metal is easy enough to break so if I ever need to adjust the fire selector, the cover is still removable.



Once I topped everything off with a Swiss Arms C-More sight lookalike, the gun was in fielding condition. The sight is nice in that is has built in iron sights, which this gun would otherwise lack. Not that they're very important in airsoft, but it's that extra bit of realism that really works for me.

I played with the gun in a few weekend skirmishes, and while very nice to handle and fairly accurate, there was something missing. At times BBs would fly off course for no apparent reason, and I was hoping of a bit higher rate of fire.

So, back to the workshop. I know calling a bit of table and a jumble of tools a workshop is overkill, but it makes me feel warm and fluffy and cozy inside.

The first thing to go was the nozzle that I swapped for an o-ringed one for better airseal. The ferrite motor that came with the gun went out and an Aim Top high torque motor went in. I had previously used the same motor on an otherwise stock MP5 and got a nice 20 rps out of it on a 7.4V LiPo. I was expecting the same here, since I was using a similar battery and identical 18:1 gears.

In order to fix the angle of engagement for higher rps I used a piece of 70D Sorbothane. I know 20 rps is not that high, but better safe than sorry. I'd also like to have the gearbox last as long as possible. The box had strengthening cuts made by the previous owner, so that was already taken care of.



The sorbo installation was pretty standard. Remove the stock pad, cut a piece of sorbo, glue into place and cover with the stock pad.



Yes I cut this beautiful piece myself, thank you. It fit into place as it should so I don't mind, altough a proper sized punch might be in order one of these days.

One obvious thing to go along with the motor swap was to reshim the whole gearbox. I had a hard time believing how high I had to set the bevel gear for the pinion to properly mesh.



The picture doesn't properly show it, but the bevel is sitting almost a full millimetre off the bushing surface. The rest of the gears were still surprisingly easy to shim so they meshed nicely, although I was afraid I'd run out of space somewhere, get poor contact on the piston or jam the tappet plate between the sector surface and the gearbox shell. That didn't happen, luckily, but I did have to work on the tappet a bit.



After I had shimmed the gearbox and was turning it by hand with all parts except the spring and spring guide inside, I noticed that there was a clear spot where the gears would not turn without significant extra force. I found out the tappet plate was hanging on the sector gear nub at the end of its cycle. I cut and filed it down a bit to make the action smooth again. Definitely a problem I've not run into before.

Before I got to testing the gun though, I found myself doing a bit more grinding and fitting.

The first issue was with the cutoff lever, which had a bit of wobble to it. The axle on which it sat seemed a bit high for the screw to properly hold it down.



After grinding down the axle about a millimetre, the screw held the lever in place a lot better without hindering the lever's motion.

A second, quite a lot larger area I had to grind down was at the back of the gearbox. I have no knowledge of either the gearbox or the receiver manufacturer, but they simply would not mix properly.



With the back of the box ground down, it would finally sit straight inside the receiver instead of tilting forwards. Before the fix, with all the screws tightened properly, the gun would not accept a magazine because the gearbox was tilting the hop up unit so far out of place.

Since I was on a roll and the gun had exhibited some inconsistency issues with the hop-up, I went all out and built my first ever R-hop out of silicone tubing which, admittedly, I had previously purchased for just this purpose.



The R-hop patch seemed to sit in the window rather nicely, but I have not yet had the time to test it properly for long range.



A final touch was to add a fuse and fuse holder as well as a deans battery connector next to the DIY MOSFET built by the previous owner.

With all the parts now done, it was finally time to wrap it all up for final testing. The gun would chrono around 1,4J, which was below what I was expecting. In the end the reason for this was that I had used the original ported cylinder, and the sorbo pad had diminished the cylinder volume enough for it to lower the output. Swapping in a full cylinder fixed this issue quickly.

The bigger problem was that I was only getting around 17 rps from the setup, which should have been putting out a steady 20. I disassembled the gun twice to get to the root of the matter. Was it the shimming? Was the motor angle somehow off? Was the battery dying?

In the end I discovered the problem to be the wire connectors used for the front wiring harness. They heated up like crazy when shooting more than single shots every now and then, so obviously they were hindering the flow of current quite a bit.

What I opted to do was to cut the old connectors off and attach new, more heavy duty ones on the other side of the hole beneath the barrel. What this meant was that the front wiring harness was now a fixed part of the barrel since the larger connectors would not fit through, but since I wasn't planning on using a second upper anytime soon, it didn't really matter.



The new connectors still allow for the upper to be removed and now there's no need to thread the wires through the hole every single time.



The larger connectors have just enough space to sit nicely next to the hop up unit and not interfere anything.

With the larger connectors, the rate of fire finally climbed to the expected 20 rps, and the wires would not heat up anymore. Even the trigger response felt crisper since the motor was getting all the current it required.

In short: You CAN get a cool looking, well working M4 on the cheap (all parts and materials total less than 100 EUR on this build), but you might need to mess around with it before its all it's cut out to be.

Sunday 15 November 2015

Machinegunning - First Look

Some time ago (ok, it was over a month) I posted the picture below on Instagram. Now I've finally had some time to get into the project of turning this pile of bits into a serviceable MG36.



The base is a G36V (or E, depending on your tastes), which I got in a non-working condition second hand. It's most likely a JG, but it's hard to be sure. The previous owner(s) had made some interesting stylistic choices, such as wrapping the handguard in camo tape and engraving "DarkAngel" (yes, seriously) on all the larger assemblies.




The gun came with the gearbox assembled, but it would not shoot. The first thing that caught my eye was definitely the DIY selector plate. In a way I applaud this kind of entrepreneurship, but then again...



Digging into the gearbox, I found it to have been upgraded with a rather interesting selection of parts. The stock motor and gears had been swapped for an Element torque motor and helical gears, but the piston, cylinder, cylinder head and nozzle were either stock or otherwise of rather interesting quality. To top it all off, the bushings were the original plastic ones.



Shimming of the gears was also pretty wildly off, which I think is the reason the gun would not fire. Also, for whatever reason the handyman who had worked on this thing before apparently had some form of grease aversion, as the insides of the gearbox were bone dry. These otherwise nice gears have been chewed up to a point where I'm not sure if they're serviceable any more.




Other parts, such as the delayer chip, had also faced some form of violence.



As a final, added bonus, here's a pic of the midcaps that came with the gun. The attaching nubs and slots have been removed. Apparently with an axe or some other tool made for fine work.



So there we have it, a somewhat challenging starting point. The to-do list for the project right now looks like this:

  • Replace internals (I already have a new spring and some leftover torque gears [21.6:1] as well as a full cylinder, a new piston and head, o-ring nozzle and steel bushings)
  • Wire to the rear, install MOSFET and deans (I have a G36 collapsing stock that will house the large battery)
  • Fix the hop-up (the current one is pretty dicey, I'm planning on installing R-hop for range)
  • Pretty up the externals (I intend to get rid of the engravings somehow, tips welcome)
  • Acquire battery (3600mAh 7.4V LiPo on order) 
  • Acquire bipod (standard G36 bipod on order)
  • Acquire magazine (an electronically run G36 C-mag would be ideal, tips on brand welcome)
  • Rewire magazine so it feeds when the gun fires and runs off the gun's own battery
Looks like a fairly long list, but I think I'll manage nicely. The biggest issue regarding the build will definitely be the magazine at this point. It needs to feed reliably and be replaceable as quickly as any other magazine, so it can't have any connecting wires. I'm thinking of something similar to the trigger contacts on the bottom of the gearbox and top of the magazine. 

That's all for now, let's see how this thing develops!