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Magwells Classic Army MK46 / M249 Guide


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Old December 5th, 2015, 14:59   #1
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Join Date: Sep 2012
Location: Edmonton, AB
Magwells Classic Army MK46 / M249 Guide

Ladies, Gents,

Some of you may have read through what I'll call my build thread of my A&K Mk43 Mod 0 (M60-E4) The A&K and Classic Army gearboxes are nearly identical, it's worth a look for some interesting discoveries, tricks, etc.

Here is a PDF guide to the CA 249, useful:

Anyway, on to the Classic Army. I had trouble finding really anything for the CA MK46, the internet seems to be flooded with information about A&K, but not CA. The following is a result of extensive internet research and personal experience. If you have a differing opinion, please voice it. I too am human, I too can be wrong.

Brand/model comparison:

G&P: V2 gearbox, regarded as the best externally, criticised for the V2 design which is more suitable to front end gearbox stress. It should be noted that the other brands use standard V2 parts in a different configuration, but the V2 design advantage would be the Lonex drop in gearboxes. The CA/A&K style gearboxes are actually much easier to work on than a V2.
Classic Army: Appears to be a Top/Star clone, solid build quality, good externals but not quite as good as G&P externally. Excellent gearbox design.
A&K: Classic Army Clone. Lower quality, but is quite a bit cheaper. On my M60 I found that I had to take the entire gun apart and apply locktight to all screws or the thing would flex like a mofo. I would anticipate the same here. A team mate has an A&K 249, I'll update when we tear into that one.
Echo 1: Re branded A&K


Realism: The real SPW modified version of the 249 had the AR Magazine feed system removed to save weight, along with the front mounting points for attaching to vehicle and fixed position mounts. The G&P appears to be the only version which truly represents this as it is a direct bottom feed system whereas all the others use the AR magazine system to feed BB's - in Airsoft I see that as a plus, although if you want realism the answer is pretty clear.

The CA MK46 comes with a 'ranger' style stock whereas the others come with a true MK46 retractable stock. This is due to CA cutting a corner and not engineering a proper battery compartment. As the basic CA 249 is rear wired it appears they just went 'meh use a nunchuck' and that was that. If you want a brick battery the wiring will need modification. I'm not sure where the other models store batteries however.

Oddly enough the MK46 was a later modification of the 249 after the SPW. As a result some images I have found appear to be M249's converted with various SPW parts. The point being the SPW and MK46 are not the same weapon, but the CA lists the airsoft gun as an MK46 SPW when in reality it appears to fall into the category of a 249 with updated parts.

Weight: Based on weight listings from distributors the CA appears to be the lightest at 5900g (13lbs). This may be due to the fact that the CA does not come with a box mag, but only a high cap AR magazine. Regardless it has the lowest listed weight. When I weighed it with an empty A&K box mag and no battery it weighed in at 13.3 lbs (6030g)

G&P: 6750g
CA: 5900g
A&K: 6400g

Price: The G&P is by FAR the most expensive. The following prices are per one Canadian retailer which stocks all three, not including GST/HST or shipping:

G&P: $999.95
CA: $589.95
A&K: $779.95 (Sale price of $479.95 [add $20 for tan], which appears to be a semi permanent sale as other retailers carry it for about this price)

Conclusion: Any of these models will make for a good support gun. Deciding which one is for you should be done by yourself. Determine what characteristics are important and go from there. As an SG you should know how to take the entire gun apart and rebuild it yourself. The intent of this guide is to assist you and will focus primarily on the CA MK46 which has many features in common with the A&K.

The CA MK46:

I'm pretty pleased with the overall quality. The gearbox design is much better than my A&K M60. All the pros with none of the really weird design features. Out of the box it was shooting 425-430 FPS @ 16 RPS

Gearbox internals were not that great, but the shell is excellent. The spring guide is plastic but mine was cracked. Cylinder had a big 'string' of metal sticking off the end remaining from the manufacturing process. Both the piston head and spring guide have thrust bearings. Gears look pretty standard, the trigger switch is a much better version over my A&K M60, and by better I mean the quality of the plastic. The A&K triggers will crack easily when you tighten the '60's gearbox screws which leads the trigger switch to literally disintegrate. Wiring is solid and simple but it will be replaced with a higher quality of wire. It does have what looks like an aluminium cylinder head with sorbo pad though, similar to the modify series but a different hue of blue.

Above picture shows a new spring guide attached, the original is to the right.

Box Mags:

I purchased an A&K box with the MK46. It fits but wobbles badly. Applying electrical tape to the shoulders of the mount on the box mag will solve this.

I re wired my entire gun with a GATE mosfet... split the wires running to the motor and routed them above the hop up to the feed tray. Then modified my box mag (super easy to take apart). I wired two wires directly to the motor contacts and routed them through the AR end cap where the sound sensor went. Drilled a hole, brought the wires back out, then around behind the magwell and they plug in via deans to the wires run from the gearbox motor. This means when you pull the trigger it runs the gearbox and box mag in tandem.

You can easily store a brick battery in the large type M249 box mags if you like but keep in mind this removes the possibility of dumping the box and using stick magazines if you need to (ie out of ammo, team mate supplies you)

A few links on different ways to wire up the box mags:

The Mag brand 'nutsack' 100rd (2500 bb) magazines appear to be one of the best built mags but are very expensive.

Edit: Do not buy new trigger switches from an airsoft retailer. The CA switches are listed at around $20 CAD, when in reality they are an extremely common micro switch. Do a google or eBay/Amazon search for: XV-152-1C25 micro switch. For example I purchased 5 of these switches for $7 last week.

Last edited by Magwell; April 22nd, 2018 at 14:26..
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Old December 5th, 2015, 17:34   #2
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The CA is indeed a copy of the TOP M249 with the PGC gearbox (the TOP design came with a proprietary system -- CA cloned both the body with the more convenient aftermarket gearbox).

And I'll open a tangent about A&K M249s since I've used one for several years (~2009) and would add a few points:

Stock, the gears are covered in a really thick, cosmoline kind of grease: I would recommend anyone take it apart and clean them up (alcohol and a soft toothbrush will be your friends) and then re-grease them properly;

I can't say for CA, but A&K gears aren't 100% compatible with V2/V3, namely the sector gear: the little peg that pushes the tappet plate back is slightly "lower" (closer to the shaft in the radius of the gear) than other gears I had; using regular gears resulted in the tappet plate being bent upwards into the path of the spring/piston and the mechbox seizing up. Some aftermarket gears may work: the ones I had on hand (Systema straight cut, Modify Torque up, Guarder steel, and stock TM) did not. That being said, once cleaned up the A&K gears were actually nice and appear to have some steel in them;

The stock piston, piston head and cylinder head suck: get better ones. Make sure they seal properly (A&K users know what I'm talking about);

Parts are almost all compatible with CA and a lot of G&P and TOP externals, so for a CA user the same should be true (often times parts, like stocks, are listed as being for A&K only but clearly they'll fit).
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Old December 6th, 2015, 17:41   #3
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Thanks for the contribution Drake

Magwells MK 46 upgrades:

The goals for this project, and reasons I picked the CA over other brands are:

1. Reliability: Reliability is foremost over FPS, RPS, weight, looks, 'cool' factor, realism, etc.

2. Weight: The MK43 M60 weighs in at around 14 lbs, and loaded up in my configuration came out at a whopping 22 lbs. Add 30 degree dry heat and you get pretty worn out at the end of the game. I'm in pretty good physical shape but found I got dehydrated extremely quickly, and wasn't as effective to my team as I really should have been. Plus that weight means I'm moving that much slower. Going from one of the fastest guys on our team with an M4 to one of the slowest was pretty frustrating lol. Where the '60 shone was wide open ground and siege type applications. Last summer I had 5 of 9 towers in a castle structure suppressed from behind a car for example, largely in part to being able to carry ~4000 bbs in the box.
The goal moving forward is to be as light as possible while maintaining a large magazine and reliability. My target weight is 14lbs loaded with all accessories and attachments.

3. Quality: Quality of parts is essential. This doesn't mean it needs to be expensive, it just has to work and not break down.

4. Realism: All aspects of the gun should either be modelled after the real deal, or could logically be added by a real life operator.

5. Cool Factor: Your goal as a gunner is to suppress the enemy so team mates can move. It's your job not necessarily to get kills but keep the enemies heads down. Your weapons system can 'open lanes' for friendly movement and 'close lanes' for enemy movement. Having the most BA looking weapons system on the field doesn't hurt

Now to the actual upgrades...

Below is the gearbox with original parts, but new wiring:

And here are my choice of parts for this build:

SHS lightweight polymer piston with steel rack
Lonex Cylinder
Lonex V2 cylinder head
SHS aluminium M4 nozzle with o-ring
SHS V2 spring guide
Modify aluminium piston head
Lonex 16:1 high speed gears
Madbull 6.03 363mm inner barrel. This may be replaced with a 6.03 380mm Promethius inner.

More parts (ie hop up) will be replaced down the road.

I'm happy with the stock motor, CA high torque.

The SHS nozzle is actually a little too long. I saw this on my ICS M4 which as it turns out has an MP5 length nozzle. I suspect this is the case here, basically the entire taper needs to be removed then re-tapered with a file and 400ish grit sand paper to smooth it out. It should be noted that the CA nozzle does include an O ring, but I didn't know this going in and have had excellent results with the SHS nozzle.

Edit: Apparently this is an SHS nozzle thing, and they are slightly longer than a standard M4 nozzle. While my ICS does have an MP5 nozzle, the M249 uses a standard M4 nozzle

With a Prommy 120 spring it was shooting at 23RPS (1380 RPM) and 417 FPS. Going to drop this a bit, the target is about 19 RPS @ 400 FPS.


Originally I was going to go to a box mag battery system; fit my 2200 MaH 9.9V LiFe batteries in the box mag, it will easily hold them and it's pretty convenient. The downside to this is if I decide to use the nutsack mags, or God forbid, I need to borrow M4 mags from a team mate since I'm out of ammo. I thought of alternate wiring to swap a battery over in this case but it's too many variables. Chances are you would get hit anyway meaning you go back and reload. At best you would be ineffective for a minute or so trying to get all the wiring sorted. I was thinking of somehow adding it to the rear which seemed to be the best location as a teammate pointed out for weight balance. Three of us had a bit of a brainstorming session last weekend and one suggested a ready mag, boom light bulb! He was really on to something here and I ran with it...


1x ICS 'Canadian' Pmag high cap that came with my ICS M4, never used. I used automotive body filler to fill the holes in the bottom of the mag, and sanded smooth. Will paint later.
1x ICS Ready Magazine System (G&P would have been fine too, I could just get the ICS for less, and faster)
1x Mission First Tactical MFT Minimalist Stock (The CA has a milspec buffer tube btw)

Add a hammer, vice, vice grips, drill, and some elbow grease and you have a Pmag battery box mounted to the lightest stock on the market!


Last edited by Magwell; April 22nd, 2018 at 14:37.. Reason: Adding content
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Old December 9th, 2015, 00:43   #4
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So finally got a chance to weigh it...

A&K MK43-Mod 0 w/ Eotech XPS3-0 replica weighs in at 14.7 lbs. (no box, battery, etc, literally the MG and an optic)

The CA MK46 with battery, box mag, forgrip, dummy 5.56 rounds, and the same XPS3-0 rep weighs in at 14.9 lbs. I know you can do the math but 0.2 lbs difference, I was pretty thrilled even though it was already over my target.

Add 2400 bbs and it tanks in at 16.2 lbs (note that the bipod has been removed, although the weight is comparable to the Eo XPS3-0, so likely negligible difference). Compared to 22 lbs, that's not bad... But it's still a little on the heavy side although as far as LMG's go it's a light weight. There are a few things I could drop, iron sights, the upper rails, fixed mount attachments... But I love the way it looks right now. So maybe I'll just live with it...
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Old December 20th, 2015, 16:27   #5
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Small update...

Our team had a tech day yesterday giving me an opportunity to try some other springs.

With a Modify 120 spring she shoots 410 FPS (no hop) at 22 RPS. I took the Gate MERF 3.2 mosfet from my M60, which allows for adjustable ROF via the mosfet, and took it down to 70% which gave me a nice 19.5 RPS. The problem, and in hindsight this happened on my M60 as well, is that with the box mag wired in line with the gun it causes feeding issues below a 90% ROF. So I ditched this and tried using different batteries. I did the math and the brick batteries kick out something like 86 amps (max draw) to the motor, so I used lower and lower combined amperage batteries but with really no tangible change. My 3 year old 9.6v NiMh which had not been cared for well from a charging perspective pulled 20.5 RPS... and it has sat for the past 6 months since I last charged it. My conclusion is that the motor is not drawing the full 86 amps from those brick batteries but is operating at or near it's maximum draw with every battery I have. This means I'll get plenty of run time with a single brick battery and there is really nothing I can do to reduce the RPS unless I start adding weight to the moving parts, or get some really low powered batteries. Like 20C burst 1000mah... So I will stick with 22 rps, keep a close eye for any damage to the internals, and use disciplined high rate of fire bursts. The thing sounds like a damn mini gun which I wont lie, is pretty awesome and should scare the crap out of OpFor.

With this settled I turned to the box mag. The electrical tape I used to take up the wobble in the box had been chewed up after only a few times of removal and re installation, so this would not be a long term solution. Further to that after a decent burst I would hear this weird whirring noise from the box which I can only assume was the counterweight spinning after the trigger had stopped being pulled. This may have somehow been a bi product of the active brake on the mosfet. It also wouldn't catch after winding the mag.. after letting off the trigger all the built up tension in the box would unwind which was pretty annoying. I assumed this was just how the box was built.

Anyway I took the whole thing apart and couldn't replicate the whirring issue with it out so I took all the gears out and lubricated them, since there was no lube, put it all back together and tested the box. Strangely enough this fixed the issue. It also fixed the unwinding and allowed the gearbox to build up tension and hold it rather than release.

I took the foam from my GATE mosfet packaging, which works perfectly for this application by the way, and used hot glue to permanently fix it to the 'door' of the box mag. Before gluing it in place I test fit and cut the foam to size. The purpose of this is to completely isolate the BB compartment from the actual mechanical mechanism of the box. Without foam or some kind of separation here, bbs can and will slip through and can cause the box to jam up. Any soft / low density foam will work great for this. 1/2" thickness is ideal. Styrofoam and other high density foams will not work as they are too dense/stiff to form to the shape of the box mag.

A team mate suggested using velcro on the 'wings' of the box mag where it slides into the retaining clip. A small piece of loop side velcro on either side fixed the issue with near zero wobble. EDIT: We tested the box mag fitment on my team mates Echo 1 (Re branded A&K), fitment of the box mag is identical to Classic Army. In other words this mod should be done to box mags for both CA and A&K


Last edited by Magwell; April 22nd, 2018 at 14:39..
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Old December 29th, 2015, 20:33   #6
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Small update..

I took apart the gun again to fix the wobble on the grip and trigger assembly which wobbles back and forth independant of the receiver. The issue seems to be with the front of the trigger assembly caused by slack between the mounting point and assembly housing. I filled the gap with JB Weld since this point has no reason to pivot around the front pin. Further to that it physically cannot pivot more than about 3 degrees unless you remove the front bracket anyway.

I had to remove my gearbox in order to access the screw to drop the front bracket on the trigger assembly. As I removed my gearbox I noticed a small ball bearing drop out. Turns out the exact same bearing that blew on my M60 blew on my MK46. My assumption is that this is a high stress point for the gears, see this post for the M60 issue: Airsoft Canada - View Single Post - A&K MK43 Mod 0 - Initial Impressions and Upgrade Thread

Now this is both surprising and fortunate. I have only about 1500 rounds through the gun, all from FPS and ROF testing (and because it's fun to shoot... I sometimes need to really make sure that my ROF is accurate, and 400 rounds later...) So anyway 1500 rounds through, hence surprising, and fortunate because I discovered this now and not 10,000 rounds later at the end of a game as my gearbox locks up.

I had done some research and it looks like the CA gearboxes, and I assume A&K 249 as well, use 8mm bushings. Our team took advantage of the boxing week sales @ Airsoft Store Canada so I picked up some Lonex 8mm Bushings with the intent of swapping these into my gearbox. A Little shocking though @ 1500 rounds...

Last edited by Magwell; April 22nd, 2018 at 14:44..
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Old January 16th, 2016, 16:30   #7
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Picked up one of the MAG brand 100 round style box/pouch magazines.

Modeled after the Real Steel 100 round bags, they are advertised to hold 2500 (100 rounds more than the A&K large style boxes).

My first impression is how ridiculously overpriced they are. After disassembling the box magazine, this impression was only solidified. With that said though, they make the 249 much easier to hold in the low ready and maneuver. While the Mk46 will never be an M4 (not that it ever should be), the smaller magazine does make it much more 'M4 like' when it comes to shooting stances. The main difference being weight. A&K is releasing a 1500 round version (CA version is 1200 rounds, MAG is 2500) but the price I saw was 40 USD, compared to 100+ for the MAG brand.

After unzipping the pouch the box mag is held together via pressure + clips and pulling the top from the bottom will separate the two. The lower is made up of two halves which separate by prying/pulling them apart as metal pins and friction keep the two halves together.

The design is remarkably simple, and if applied to a full size m249 magazine would allow a person to carry upwards of 5000 rounds. It's simply a high cap rotated to lay flat and an opening cut in the side to allow bbs to drop into the cog wheel.

So again after lubricating everything, which had more lube than the A&K box, but not nearly enough, I desoldered all the wiring and remove it then soldered on some 16AWG milspec silver wire. This was then run up to the top of the box, and then to the connection under my feed tray cover.

Then I cut some high density foam down and shoved it into the hole where the 9V battery would go, to prevent bbs from falling in here as the magazine was filled up.

It fed just fine off a 9.6v and will probably work just fine with the gun although I haven't done a full test yet. The size does make a big difference though as it's total volume is about 1/3 of the 200rd style boxes

Edit: The motor on this box is about half the size of the ones from the large '200' round style box mags. While the large box has no trouble keeping up with 22 rps, this little guy maxed out somewhere between 14 and 20. Even if I ran it independently of the gun to build up spring tension the gun still dry fired about one out of every three rounds. Based on the design I'm not sure if it can be modified easily to hold a larger motor, we'll see.

So far though I'm pretty disappointed. These have some pretty big hype on the forums I've read through but they lack in quality of workmanship, performance, and are about two to three times the price of a CA or A&K 200 round style box. The only advantage these little mags have is their reduced size. The CA 1200 round box mags are likely different but also over priced. I'll be picking up one of the 1500 round A&K box mags when they come out and see what those are like, and probably just re-attaching the original wiring to this MAG box mag and selling it.

Last edited by Magwell; April 22nd, 2018 at 14:49..
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Old January 24th, 2016, 22:03   #8
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Finally got a chance to replace the bearings for bushings. There was virtually no damage to the gearbox or gears since it was caught relatively early. If you do nothing else to your gearbox, replace the bearings for bushings, I cannot stress that enough.

8mm Lonex bushings were installed, and then I spent the better part of 4 hours finishing off what I daresay is the best shim job I've done to date!

With everything re-installed I re-chronoed and am pretty happy with the results, minimal ROF loss and still shooting right where I want it with zero hop applied!


Last edited by Magwell; April 22nd, 2018 at 14:52..
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Old March 6th, 2016, 22:02   #9
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With the temp hitting +11 yesterday, I went out to our teams practice field with some team mates and we ranged several guns.

With the stock barrel and hop up, my MK46 was able to consistently hit a team mate at 230 ft with short bursts despite a cross wind, and if I stretched it, able to lob out to 250 ft inaccurately. This was not measured with a tape, but paced out so the distance may be a little off, suffice to say over 200 ft easily.

With baseline testing completed I'm going to add the 6.03 TBB, Bullgear Hop Up, & Flat hop the assembly to try and hit 275-300 ft semi-accurately.

The whirring noise referenced in post #5 is also back, but much better. Assuming this is caused by the active braking on the mosfet I wired in a rectifier diode (1N4007 - although any 1N400x diode should work) which forces electrons to move only in one direction. In other words this is like a one-way valve for wiring and will prevent the active brake from turning the motor in the gearbox. We'll see if this solves this problem.

Last edited by Magwell; April 19th, 2016 at 00:08..
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Old April 3rd, 2016, 19:10   #10
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I received a few PM's about the wiring set up on the box mags so the following is a short DIY on what I have done. Note that this wiring system runs the box mag in tandem with the gearbox so it has two wires running from the motor to a connector which attaches to the box mag.

Step 1: Disassembly.

1A - remove the two screws on the underside of the gearbox.

1B - remove the screw holding you magazine insert together.

1C - Remove the boxmag internals.

1D - desolder and remove all wiring.

Step 2: Modification

2A - Drill a new hole in the magazine insert for the wires to exit and connect to the gun. This could be done in many locations but the one pictured is how i decided to route my wires.

Step 3: Wiring

3A - Solder your new wiring in place. Make sure to check which terminal is positive and which is negative on your specific gearbox as it may be different than mine.

3B - If using an active brake mosfet, wire in a rectifier diode to the negative wiring. What this diode does is only allows current to flow in one direction, effectively preventing the reverse polarity from the active brake mosfet from doing anything to the box mag. If you are not using an active brake mosfet, disregard this step. Any 1N4001 to 1N4007 diode will be sufficient.

3C - If you used the diode in the above step, cover it with heat shrink. After that solder the negative wire to the negative motor terminal and run both the positive and negative wires together to the notch shown below. Leave slack so the wires are not tight (ie would get ripped off the motor contact if pulled) and use electrical tape or hot glue to secure them in place if desired. If using a long strand of heat shrink to keep everything tidy, this would be the time to apply it.

3D - run the wires through the same coil spring that housed the microphone wires, then through the hole you drilled in step 2A. Measure out enough wire to reach the mag insert and have some slack inside the box mag. Wrap some tape (or hot glue) the wiring as shown to prevent it from getting pulled through the hole.

Step 4: Reassembly

4A - reassemble your box mag. Feed the new wiring and half of the magazine insert through the hole in the box mag along with all the springs. Attach that U shaped filler back in place once the entire mechanism is back inside the box by seating the back end in place, and applying pressure to the front then pushing up. It should click into place. Re install the two screws removed in step 1A then put the magazine insert back together with the screw removed in step 1B

Step 5: Final Wiring

5A - Install the box mag to your 249 and route the wire from the magazine insert to the power source coming from your gearbox/battery/mosfet. Cut the wire to length and solder it to the connector of your choosing, preferably DEANS.


Last edited by Magwell; April 22nd, 2018 at 15:02..
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Old April 19th, 2016, 00:16   #11
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Ok, fairly large update:

Fixing the Hop Up.... While the stock hop up seems to work ok, it's plagued with some unique design flaws:

1. O ring - the O Ring is needed to keep the hop up wheel from rotating, or falling off. Using an O Ring that's too small (Lets face it, they dry out and crack/break over time) will allow the hop up to back off to zero very easily. Regardless of the Hop Up, the O ring should prevent the wheel from free wheeling/spinning easily.
2. Nub, or... what is that? Normally (Ie basically every other hop up design) hop ups use an arm which has a half circle notched out to accept a cylindrical nub, placed horizontally. The M249 hop up rotates this nub 90 degrees so it sits vertically, like a barrel. This means you cannot use any kind of non cylindrical nub, and a portion (let's say something like 20%, just a W.A.G.) of the arm movement is lost due to compression of the nub. If retaining the existing hop up, cut the end off the ink reservoir from a pen and use that instead to maximize hop up adjustability & tuning.
3. Barrel retention clip. It's plastic and seems to like to move around/fall off easily in some cases. Keep an eye on it when the hop up is removed and make sure the barrel is locked in.

So what options do we have? The Bullgear (also sold under different names) hop up makes a hybrid of the typical hop up and the M249 hop up. This allows for a larger window opening for use with flat hop nubs, H nubs, etc. It also has a C clip which is secured with a locking screw, preventing the barrel from loosening at all, unlike the original plastic retention clip. This is the route I chose, combining a flat hop with a 6.03 Tight Bore barrel.


1x Bullgear CNC Aluminum Hop Up
1x Firefly Namazu Flat Hop Nub with Roller Bar
1x Madbull 6.03 Tight bore Barrel (363mm length - this may be different depending on your M249 model)
1x Prometheus Purple Bucking


I used this video for reference:

1. Disassemble the hop up, check the window opening, cut the Firefly nub to suit and install the roller bar.
2. Turn the bucking inside out, use a knife or dremel to remove all material protruding from the bucking (ie alignment channel and contact patch). Invert it again so the bucking is in its original shape.
3. Insert the bucking on the barrel, rotated 90 degrees so you have a clean contact patch. If you like doing any other mods, ie dental floss, do this now.
4. Insert the barrel and bucking into the hop up, spray lube or water may help if its tight.
5. reassemble the hop up, install the barrel retention clip, dial, and O ring. It's a great idea to head out to Canadian Tire (Or Home Depot, or wherever) and just grab an assortment of plumbing O rings. You can test fit various ones to find the ideal amount of friction on the dial.
7. Barrel modification. On my M249, I had to dremel a bunch of material off the inside of my outer barrel in order for the new hop up to move in/out freely. It would bind up and not allow the barrel to seal correctly with the gearbox otherwise. See the pictures below.

So, what kind of effect did the new hop up, barrel and Hop Up system have?

Chrono results:
5 FPS drop over the stock barrel/hop up/bucking combination when tested at 19 deg C indoors. When tested outdoors in +23 deg C, there was no FPS difference.

Range results: We measured a range out this time, setting targets every 25 ft... Conditions were: +23, slight wind (11km/h gust), sunny, 10% humidity.
250 Ft accurately, 260 Ft inaccurately (BB spread seemed to widen this last little bit... some dropped at about 255 ft, others continued), and able to lob inaccurately to 270 ft. At 270 ft it's a waste of ammo, at the maximum range, dropping BB's at a person's feet - acting out the Matrix would be super easy... A team mate was down range for the finite ranging indicating BB hit locations. A stationary human size target (in this case an actual human lol) is very easy to hit at 260 ft.

Trajectory: The BB trajectory is slightly different, rather than a more or less straight flight path with an arc at the end then dropping off... the BB travels more or less perfectly straight, hops very slightly, then drops rapidly.

All in all, I'm pretty happy with these results. Can't wait to game it!

Last edited by Magwell; April 22nd, 2018 at 15:10..
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Old May 9th, 2016, 23:56   #12
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Ok, update...

Finally got a chance to game this gun over the past two weekends. The first game was A LOT of patrolling, not much shooting. Pretty unique though creeping around for a change, and none of our squad died during the entire game - certainly a first there.

The second game was much more shooting. Around 150 people in a medium sized field... constantly shooting and getting shot lol. The MK46 worked absolutely beautifully -until- dun dun dun.. something broke.

I'll preface this with saying I think this has happened before with Lonex spur gears but I can't remember on what gun. Anyway my damn spur gear broke. It didn't shear teeth, strip, etc. No... whatever is holding the two gears on the spur let go meaning that the motor, bevel, and half of the spur were able to spin normally, but the the other half of the spur and the sector then piston just sort of moved back/forth as the tension built then released due to the gear letting go about the axle.

The symptoms sounded like a stripped gear or piston, I actually thought at first that I had shattered my piston since it's a light weight one, then thought I stipped my pinon gear on the motor. It would whine like the whir of death when a piston strips for a second then the spur would seem to lock up and shoot. So whiiirrrrr pa pa pa pa pa pa. Honestly though, it's a fairly harmless failure. Literally everything in the gearbox is 100% fine except for the spot weld or pressed section of the spur that holds it together, vs an exploding gear raining death and destruction into the cylinder and motor.

So, damn I really didn't want to re shim after such a good shim job. So... Solutions... In a word, Siegetek. Yes Siegetek "never ever break on you, just give us your first born in exchange" gears. With our poor CAD it's pretty pricey but hey if they never break then I'm ok with that. The downside is they don't have 16:1 gears, the closest is a whopping 14.09 (why we get into hundredths of a gear ratio for Airsoft I have no idea, this isn't a transmission...) I digress. I did rough calculations, and with my current ROF around 21 RPS (1250 RPM) 14.09:1 throws it to 23.8 if I remember right. Yes, 1450 RPM, or an entire CA nutsack mag in less than a minute. Heh. Well. I won't lie a part of me is kind of in love with the idea but the more conservative side is saying that's too much fire power.

So.. solutions:
1. Heavier piston = more moving mass = more energy to move, therefore takes longer to cycle. Could also just add washers/bearings to the piston and remove it from the spring guide.
2. Lower powered batteries. Although, after having a very healthy stockpile of batteries for my LMG's specifically I don't want to buy a new set for one gun.
3. Adding resistance to the system, possibly wiring the box mag in series rather than parallel, although I need to double check the effects of each on the electrical system, may not help.

I'll decide later and post up more once the gears get here... and I reshim, again.

Time for pictures... I decided to paint my LMG. Because, awesome, and because camoflauge. Which does actually make a huge difference.

Oh, and I'm now running a real steel T-Pod G2 bipd/grip, painted to match. Purchased through Wolverine Supplies in Manatoba, great guys go shop there if you need RS stuff, seriously amazing service. Anyway it's the same idea as the grip pod but beefier. Also has some cant to it and lets you set each leg individually if needed for uneven terrain. Don't bother with the repros if you can afford the real one, the chinese knock offs are poorly made. Well, no really? Duh. But seriously, they are crap. Get the RS one. Info:


Last edited by Magwell; April 22nd, 2018 at 15:17..
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Old May 24th, 2016, 23:47   #13
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Join Date: Sep 2012
Location: Edmonton, AB
Siegetek 14.09:1 gears arrived last week... Team had a tech day on Saturday so I pulled apart my gearbox and dropped in the new gears + reshimmed and relubed everything.

The air seal was improved with the reassembly, noticeable by a small bump in FPS (back to 413 from the 5 FPS loss with the new hop up) and a small consistency increase (+/- 3 FPS now vs +/- 6 FPS before)

To combat the increased speed of the gears I moved the bearings from the spring guide to the rear of the piston, adding weight, and used a plastic spacer in place of the bearings on the rear of the spring guide. RPS increase is minimal at ~1.2 RPS with the box mag and 2.2 RPS with an M4/M16 STANAG. This translates to ~22.5 RPS with the box mag and ~23.5 RPS with a STANAG magazine. Given the huge increase in reliability I can live with the increase, which honestly is fairly minimal as I'll be using the box magazine 99% of the time.

Funny to put it in perspective though; 1 midcap every 5 seconds with continual fire lol.


Last edited by Magwell; April 22nd, 2018 at 15:19..
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Old June 8th, 2016, 23:33   #14
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Join Date: Sep 2012
Location: Edmonton, AB
Gamed it a week and a half ago with the new gears, and used it at a team practice last weekend.

So far the gears are performing beautifully, but with that solved I discovered a couple other things.

1. A good reminder to apply blue Locktight to all screws in the gearbox... Forgot to lock tight the screw on my spring guide in place so that was doing a nice dance inside my spring/piston lol. Fortunately it stayed inside the coils of the spring.

2. Some of my bushings have started to slip and actually spin the the gearbox housing, it's happening on three of them, two on one side, one on the other. Planning on removing the bushings and applying a little JB weld to the walls of the bushings, then inserting back in place and re-shimming. These bushings should never fail so welding them in place isn't too much of a concern. If they ever did a hammer and punch should get it out easily enough anyway.

Quick shot of me suppressing the enemy as we moved... Moving through the open putting bursts into a tree line where the enemy was in cover.


Last edited by Magwell; April 22nd, 2018 at 15:22..
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Old August 13th, 2016, 16:37   #15
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Join Date: Sep 2012
Location: Edmonton, AB
Time for another update... Picture intensive!

Been pretty busy this summer, so Airsoft has taken a bit of a back seat but I finally got around to getting back to work on this gun. Ordered an A&K 1500 rd 'nutsack' box mag via Evike (seems Evike has a monopoly on these, can't find them anywhere else). The price was 50 USD, (vs ~110 USD for the MAG brand). So far, I'm very impressed. If you're looking for one of these, skip out on the MAG boxes and go right for the A&K, there is NO comparison between the two, and for less than half the price... Here is a link for those interested. I should note that the multicam version is no longer up on the website (I ordered 2 weeks ago). I have no idea why, but I assume they are sold out.

The box mag runs off its own proprietary battery pack (4x AAA batteries, in a sealed unit, rechargeable), and comes with it's own charger and pressure switch if you want to run the box that way. Proprietary rechargeable batteries aren't my thing though, so I tossed it immediately and started the rewiring process to bring it up to par with my other box magazines.

Before I get into that a quick comparison of the two...

MAG 1500 RD Nutsack
-Relatively easy to find/purchase
-Simple wiring and use
-Replaceable 9V battery power supply

-Cheap/weak construction
-Cheap internals
-Small motor (limited RPS)
-Small access door for BB's that doesn't lock open

A&K 1500 RD Nutsack

-Reasonable construction (still plastic, but better plastic than MAG)
-Powerful motor
-Robust internals (relatively speaking, still plastic, but the same bits as the larger box mags)
-Well designed
-Easy to disassemble/service
-Larger access door that locks open

-Proprietary Rechargeable battery (ie it dies in the field, your box is out of play)
-Doesn't play nice with dummy rounds (see pics near the end)
-Still overpriced, especially with our dollar, however MUCH more bang for your buck than the MAG boxes

So on to the actual box...

Once the fabric cover and top are removed, the internals are very clean, it's pretty much impossible to get BB's into the mechanism from what I can see, an improvement over the larger 2300 rd box mags.

After removing the battery and bottom of the box, we gain access to the electronics, which are more or less the same as the larger box mags but with added circuitry for charging the rechargeable battery.

A few more screws and the mechanism is easily removed (would be nice if it was secured a bit better, but it works. Not as robust as the larger style boxes though.

With the original wiring removed, I added 16 AWG milspec silver wire as with my other boxes. Can't forget that diod! (see earlier posts for why)

Heat shrink that connection...

To get it past the side I removed some material at the flange and slipped the wires past, routed them to the spring where the sound sensor went and use hot glue to secure it in place. Make sure to test fit the lower cover before the glue cools down so it can conform to the shape if needed.

As with before, a new hole is needed in the magazine insert. Route the wire and hot glue in place.

I used the two screws which held the circuit board in place to screw in on the left/right of the box. This is to hold the top in it's proper place until the other screws get inserted again. Because they go through the fabric it's very hard to actually find the holes - case in point at the top right hole here which the screw missed as they assembled it in the factory. It's not a huge issue but the box sits cockeyed otherwise and you lose storage capacity.

And here it is all assembled and installed.

The access door is easy to get to, although the button that secures the zipper takes quite a bit of force to undo - will be difficult with gloves if you need to reload in the field. Some wear might make this easier but keep that in mind. Also notice how the feed tube sits over the dummy rounds... The larger box mags have some flexibility as the spring can slide in/out. This is not the case here, both springs are fixed at either end.

After testing this my RPS shot up by 2 RPS (assuming less resistance on the motor in the box mag). These little mags can chew out 24.5 RPS easily, but that's too much fire power for my taste - going to modify my electronics to try and bring it down to 19-20 RPS. Very happy with this mag though, I can actually use the gun in the low ready, no more 'chicken wing' when using the forward grip. All in all much more comfortable and maneuverable!

Last edited by Magwell; April 22nd, 2018 at 15:29..
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