A&K MK43 Mod 0 - Initial Impressions and Upgrade Thread
 

Hello gents, being as there is not a ton of info I've found on this guns internals I've decided to post this thread.

Recently had one ordered, arrived Thursday, Nov 27.

Very solid gun, but mine had no duck bill flash hider or bullet belt - disappointing. Shoots beautifully though! Chronoed at 428-430 FPS constantly with zero hop. Slightly disappointment in how 'dead' it feels. My other AEG's offer some feedback via a small amount of recoil. This M60 is likely too sturdy and dissipates the forces internally. it's made primarily of metal.

INTERNALS:

Opened it up yesterday, and I'm surprised it was shooting that hot given the internals are pretty much crap except the gearbox shell, gears, and cylinder. The piston, piston head, cylinder head, and nozzle are all poorly made plastic with really small o-rings. The piston was showing signs of wear after less than 200 rounds, and should likely be replaced along with the piston and cylinder head right out of the box for longevity. The spring guide seems good and looks to be a V2/V3 type attached to a spring guide extension for the quick change system - also had a thrust bearing. Gearbox/air seal grease/lube was more or less non existent. The spring is about 75-80% of a normal spring length. Will replace with a new spring once air seal is optimal. The bearings seem good, but needed to be re-seated as they were not inserted fully into the gearbox shell.

The majority of the internals were replaced with:

-Matrix one piece CNC cylinder and cylinder head.
-Magic Box Double O-Ring Aluminum Bearing Piston Head
-Mad Bull PX Piston W/ Steel Rack
-King Arms Tappet Plate (Broke, used original instead due to slight differences)

Shimmed, sanded out the guide rails in the gearbox to remove burrs and lubed/greased all parts.

chronod at 365-366 FPS consistantly. I have yet to fully check it but it seems the nozzle is the culprit. It has up/down and left/right play. I would imagine the original cylinder head had a larger bore than the Matrix one, or the parts were just poorly designed. Ordered a Angel Custom Teflon Coated Enhanced Nozzle for A&K M60 Airsoft AEG. This should help with air loss. I also ordered a Modify SCAR series nozzle w/ o ring as this can be cut down to fit the MK43 if the Angel nozzle is designed for a larger bore cylinder head.

Parts on order, to be incorporated:

-MODIFY VERSION 3 Rotary SPRING GUIDE W/ BEARING
-Angel Custom Teflon Coated Enhanced Nozzle for A&K M60 Airsoft AEG.
-16AWG wire
-BBA Motor Connector Set (Type A)
-GATE MERF 3.2 AEG Mosfet Control Unit
-Mad Bull 1inch Barrel Extension 14mmCCW (For new compensator)
-Lonex Titan A1 Revolution Short Motor
-Modify Air Seal Nozzle - SCAR Series
-Mad Bull Noveske KX3 Sound Adjustable Flash Hider Black


The rheostat to adjust ROF will be removed as it uses an ~5.5" heat sync - lots of wasted energy. The gun will be fully re-wired with 16AWG wire and a mosfet added.

BOX MAG:

It takes some practice to get on/off but is solid enough design. Feeds very very well, we'll see how it holds up. A replacement is pretty cheap from E Hobby Asia as well.

More to come!

Update:

Well here she is in her current configuration, I measured and drilled into the feed tray cover to bolt in a rail for the Elcan, it's aligned nearly perfectly with the barrel but I still need to zero it, hence the offset in the third pic:

http://i1286.photobucket.com/albums/...psc404a817.jpg

http://i1286.photobucket.com/albums/...ps23a21540.jpg

http://i1286.photobucket.com/albums/...psc6588609.jpg

I did a complete disassembly and re assembly. Due to:

1. Re-wiring job required the majority of the M60 to be taken apart
2. To apply lock-tight to the Airsoft gun as it didn't have any from the factory. By doing this I have eliminated all the unwanted movement in the AEG including the barrel movement, it's solid as a rock!

http://i1286.photobucket.com/albums/...psb7b00e3c.jpg

So let's start off simple, what needs to be adjusted?

1. Set screw for the rear iron sign should be backed off, locktight applied, and tightened:

http://i1286.photobucket.com/albums/...ps32fb0ad7.png

2. Remove the quick release barrel, set aside. Remove the bipod by unscrewing (counterclockwise) the nut on the end.

http://i1286.photobucket.com/albums/...ps36652ce6.png

Then unscrew the entire pipe attaching it to the receiver. Apply locktight, and tighten it up good. This connection would rotate when the bipod moved. Once back on, reinstall the bipod, apply locktight and tighten the retaining nut. Leave some space so the bipod can move freely left/right as it rotates on the barrel.

http://i1286.photobucket.com/albums/...ps8f0d565e.png

3. I had some bad wobble in the trigger group. To correct, I removed it and bent the retaining tab in the receiver up to apply more pressure. There is a pin you depress on the front left of the trigger group, then it will slide out similar to body pins on an M4.

http://i1286.photobucket.com/albums/...psf145548d.png

Internals:

Here is the gearbox, the one pictured has a new piston, cylinder, cylinder head, and has been cleaned out/shimmed.

http://i1286.photobucket.com/albums/...pseec0f11a.jpg

http://i1286.photobucket.com/albums/...ps3730237e.jpg

Quick change spring guide:

http://i1286.photobucket.com/albums/...psf834db6b.jpg

I removed the old wiring which had a lot of un necessary runs, just a waste of wire and electricity. The rheostat burned up a lot of juice and even when you put the bit in that cancelled it, all your current is running through 2' of more wire than it needs to...

So here is the mosfet and new wiring, mosfet is accessed by removing the barrel.

http://i1286.photobucket.com/albums/...ps02028d9d.jpg

http://i1286.photobucket.com/albums/...ps81fe634e.jpg

I have yet to add the new nozzle but it was running beautifully after all this, still need to chrono on the new battery though but it hit 406 FPS @ 16rps on a 9.6v

Hi! I posted some questions a couple of months back about this gun, and I didn't get much answers. If you don't mind, I've got some questions.

How did you drill the rail on top? If you have the time, I've never seen a tutorial on this, but I've seen this mod done frequently.

What did you do with the hop up issues? Did you just do the pen mod, or are you going to mod it to fit regular nubs? I've also heard that you can replace the whole unit with a classic army hop up, but I'm not sure if that can fit regular nubs.

Thanks!

Hey man, it`s quite simple the way I did it - I`ll post some pics later today.

I haven`t gotten into the hop up yet. Being as we have all this white stuff outside I haven`t gone to range it yet. I would rather it get to +15 before I do any testing with the hop up as -5 could make the rubber behave differently. I honestly haven`t taken the hop up apart yet, it`s last on my list.

Time for an update... Got a lot done today. But first, M60 porn lol.

http://i1286.photobucket.com/albums/...ps5e6d0cdc.jpg

The new nozzle (Modify nozzle for VFC SCAR-H w/ integral o-ring) is about 1/4" too long, so I sanded it down with a file, then sanded a 45 degree angle to the ends. Finished it off with some 1500 grit sandpaper to smooth out all the edges from the burrs.

http://i1286.photobucket.com/albums/...psd9ee4655.jpg

And here is the gearbox with all the new parts, before new grease. The new nozzle fully solved my air seal issues as you will see...

http://i1286.photobucket.com/albums/...psfb41e9b9.jpg

I immidiately tested with the original spring, but with a new piston/piston head, one piece cylinder/cylinder head, nozzle, motor, and wiring. 0.2g Elite Force BB's were used with a 9.9V LiFe battery. The results speak for themselves, at 18 rps (hit 19.4 max) and 466 FPS max recorded, lowest was 454, hitting 460 FPS about 80% of the time... This is ~30 FPS higher than the gun recorded originally with A&K parts. However I have about as perfect an air seal as I can expect to have with an airsoft gun and parts that will wear better and last longer. Which is important when you'll burn between 5000 and 10 000 rounds or more a game.

http://i1286.photobucket.com/albums/...psce940ace.jpg

Next I used a Promethius M120 spring (known to behave more like an M130). It chronoed at 460 consistently, indicating that the factory A&K spring is likely an M130 spring. next I used a Modify M120, hitting 440 FPS, next a Lonex M110 spring, hitting 435 consistently. I did not have an M100 spring so I cut about an inch off the M110, and refinished the cut edge so it would stay secured to the spring guide and not slip off. It chronoed as below, 395 +/- 3 FPS. The reduced ROF could be due to the battery losing power, it's a 2100 MAH battery but I've yet to charge it and it's seen likely about 3-4 thousand rounds lol.

Anyway 400 ish FPS is exactly where I want it. I don't want to max out the power (420 FPS is my local fields rules) and this gives me some flexibility if the field chrono is reading high, and also it's a support weapon - less stress on the gearbox and I'll likely be hosing people from time to time if I suppress an area aggressively.

http://i1286.photobucket.com/albums/...ps331aa0dc.jpg

As requested - short DIY on adding the rail...

http://i1286.photobucket.com/albums/...ps3365c0c1.jpg

http://i1286.photobucket.com/albums/...psf2272caf.jpg

1. roughly line up your rail - note where the holes are in relation to the feed tray cover, place masking tape/painters tape in this area.

2. I used a laser level, but a straight edge could also work. Find center of the barrel, mark the centerline on your tape.

http://i1286.photobucket.com/albums/...pscc7367e7.jpg

3. Remove the feed tray cover (2 screws on the inside of the cover just behind the hinge.) Inside is the mechanism that feeds the belt through (forgot the name) it is held in place via two allen screws - remove this. Either re-install after or leave it out. I left it out because the bolts for the rail interfered with it.

4. Place the rail on your feed tray cover, mark the center of the holes horizontally so you have an 'x' to drill into (one edge being the centerline, the other being the center of the rail hole) NOTE: Make sure your rail is far enough back so it doesn't contact the rear ladder sight when you open the feed tray cover. Failure to do this could mean you cannot re-attach your feed tray cover, and have to re-drill the holes.

5. Using a drill press preferably (or drill) drill the forward most hole. Feed a bolt through the rail and feed cover. Use washers to make up the height difference. Bolt in place.

6. Double check that your rail is still facing forward and on center, if needed re-mark the rear centerline. Slide the rail over and drill the rear hole.

http://i1286.photobucket.com/albums/...pse89b2eee.jpg

7. Use a file to clean up your holes, mask off if needed, spray the holes matt black (or primer or w/e) to prevent it from rusting/corroding. Keep in mind when unlike metal is in contact (ie steel/aluminum) a reaction occurs causing rapid corrosion (rust), known as Galvanic Corosion: http://en.wikipedia.org/wiki/Galvanic_corrosion the point here is to isolate the metal to make sure this doesn't happen and destroy your paint job.

8. Feed the bolts through your rail, then washers, then into the feed tray cover and bolt in place. I used lock washers on the inside + lock tight to prevent the bolt from coming loose.

http://i1286.photobucket.com/albums/...ps5f9a33ce.jpg

9. Re-install the dummy belt mechanism or at the very least install the washer/screw located at the latch. It is needed to place the latch in the correct position.

http://i1286.photobucket.com/albums/...ps038adece.jpg

10. Attach an optic of your choice and dial it in!

Also some info on using a dummy bullet belt with this M60:

I have a belt of dead NATO 7.62 rounds (real bullets, no gunpowder). To fit them I had to remove about 1/4" from the tip because they are too long otherwise - and then hot glue them to some foam or they would just slide right out. The foam gets clamped in place and the pressure prevents the belt from falling out. If you are looking for a bullet belt, please search on your own.

http://i1286.photobucket.com/albums/...ps68a4de5f.jpg

http://i1286.photobucket.com/albums/...ps5372a97e.jpg

Thanks for the guide! The idea with the foam is also a good idea, can't wait to try that out. Here's another idea idea too, since the bullets go into the box mag it creates an opening where potential bbs could fall out, maybe one can add foam on the other end of the belt as a sort of stopper to stop bbs from falling out, I'm going to check today to see if that is a feasible solution myself. Thanks for the guide!

Love the detail in this thread about the mk43 internals, I have the ares one and its internals are extremely similar. Should sticky this or have it moved to gun diagrams thread for safe keeping

Yeah, this thread is the most detailed guide on this model I've seen ever. Thanks Magwell!

I'm actually working on milling out my hop unit to be able to use a regular nub rather than a vertical nub there now

I am using a promy bridge nub had to cut the wings off it to fit length wise in the inner and had to make it thinner width wise, used an exacto knife to achieve this, am using a Dremel with diamond bit to mill the hop unit, taking a while to get even a millimetre gone hahaha. Will post updates as I go

I have finished with modding the hop unit for a bridge nub. All that's left to do now is wait till I can test it. I had to mill out the hop unit towards the rear of the hop unit, meaning I was able to leave at least 50% of the tread on the front part of the unit to still use the same screw to adjust the hop. The milling took the longest, where I had to let the unit and my Dremel cool down due to it heating up while using the diamond bit.

I will post results when I'm able to test it

Thanks!

Good idea, but I just run my bullet belt over top of the box, and then down beside it, between the box and fabric rather than opening the cover. Hides all the battery wires this way too.

I was able to test the hop up today, briefly, before destroying my piston lol. More on that later.

I took apart the hop up unit completely, replaced the bucking with a Madbull blue bucking (My ICS M4 loves these so I have a handful of spares, seems to work well). I also did the dental floss mod to it. Barrel was extremely dirty, and it occurred to me I had never cleaned it, so I did. The reason I mention this is that my BBs were curving down, regardless of how much hop I applied. After taking apart the hop up, I'm really disappointed in how they designed it. The new bucking should help though, but I need to do further testing in warmer weather.

How did it turn out?

Update...

I destroyed my piston.

How? Well my ROF was too high (for the spring in the conditions), it was cold out and the aluminium cylinder shrunk. The motor turned the gears faster than the piston could cycle. This resulted in the end of the piston being ripped off.

http://i1286.photobucket.com/albums/...psmrqysxwt.jpg

http://i1286.photobucket.com/albums/...psogmnr8dw.jpg

So I replaced it with a Lonex half rack blue piston (had it for a while, works well). Problem solved. Replaced my piston head (the double O Ring one was heavy, aka more moving mass) with a red Modify Aluminum piston head. I use this one on most of my AEG's. I've run it in my ICS M4 with over 200,000 rounds through it, works great.

http://i1286.photobucket.com/albums/...pspyotlean.jpg

I then began fine tuning the FPS with springs. I ordered a Madbull M100, M110, and M120. The one I had previously settled a bit and was shooting 380FPS, too low for my taste and evidently too weak for the motor in +8 C.

http://i1286.photobucket.com/albums/...pswd1swwu9.jpg

So after this piston mishap - I programmed my mosfet to only shoot at 90% ROF, one of the great features about the GATE mosfet.

The Madbull 100 spring shot ~385 @ 19.3 RPS with 0.2g BB's and no hop. (ROF limited to 90%)

The Madbull 110 spring shot ~410 @ 18.4 RPS with 0.2g BB's and no hop. (ROF limited to 90%)

So at 100% ROF it should be shooting around 20-21 RPS. 18.5ish is good for now though, no piston issues and it will save a little bit of ammo, useful for milsims.

http://i1286.photobucket.com/albums/...psjl2w4pwz.jpg

Then I got into the hop up. I'm annoyed with A&K for such a stupid design. I changed the bucking out with a Madbull blue bucking and did the dental floss mod. Shoots more consistently now and I noticed an increase in FPS (this was before spring testing with the Madbull springs). Hopefully I can get 200 feet with this hop up, more testing will be done later.

http://i1286.photobucket.com/albums/...psmggc9tck.jpg

http://i1286.photobucket.com/albums/...psqqsdduxe.jpg

I then decided to modify the Promethius spring guide to fit - it's 'wings' are too wide to work, so they got cut down with a grinder, then filed down for a final fit. It also didn't fit the retaining screw so it was glued in place with a strong adhesive.

http://i1286.photobucket.com/albums/...pshjik2fg2.jpg

http://i1286.photobucket.com/albums/...psaieppkys.jpg

http://i1286.photobucket.com/albums/...psse9m3dna.jpg

http://i1286.photobucket.com/albums/...psrtazw2uv.jpg

It actually turned out really well, milled it out, did a bridge hop mod, other than that and a promy inner the rest of the internals are stock, I have significantly greater range using the same batch of g&g .28's than I did with the stock inner and stock hop. The difference is unbelievable. I can't even see how far the guns accurate beaten zone has been extended, even using a 4x sight. Anyone seeking pics on how the hop unit looks to see what I did, pm me.

Cool, I would be interested in seeing how it works. Post the pics and info here, keep it in one place for future users.

And what ID is the barrel? 6.03? Also - what FPS is yours shooting with 0.2g on stock internals? It should be slightly up over what is was before with a smaller diameter barrel.

Yeah it's 6.03mm promy from airsoftparts.ca, I milled out the rear part of the screw hole in the hop unit using a Dremel and a diamond drill bit, being careful to not damage the remainder of the threads for the screw. Then I placed a bridge nub on the inside of the hop unit (where the barrel goes through). It took a bit of work to get the inner with the rubber over it, to slide in under the bridge nub, but once it was in there it fit well.and once it was all in the hop unit, I placed the screw back in to the threads. Then put it all back together. She doesn't chrono much more than between 380 and 400 in position 1. Position 2 yields approx 420-430 on 0.2's

I just realized that I forgot to add one thing to my last post lol, I am using an m100 or m110 spring (can't remember offhand haha)

Update:

Gamed the M60 for the first time on Saturday - fired about 9000-10,000 bbs and it worked beautifully until I sheared 4 teeth off the spur gear!

http://i1286.photobucket.com/albums/...psmszupvpw.jpg

Upon closer examination it looks like the grease I used on my piston, piston rails, tappet plate, and nozzle either froze or got very thick (think dried wax). I ran out of my usual grease and used some stuff I had lying around... Guess I'll toss that stuff lol. I also burned through 4200 MAH of batteries, and only had an 11.1v Lipo for a back up that day, which brought the ROF to around 150% of what is was on my 9.9V LiFe batteries, I believe this also contributed to the failure. However, this would have just been a matter of time, and would have likely happened later this year anyway.

Solution? Ordered new grease and Lonex Enhanced Super Gear Set - High Speed Ratio (16:1). I'll just replace them all to prevent any future issues. The gears are also 16:1 over what I assume is 18:1 for the A&K gears. I'll fine tune the ROF with my Gate Mosfet but this will give me more flexibility to get an optimal ROF with reliability.

http://www.airsoftstore.ca/images/GB-00-04.jpg

Other than this, the gun worked beautifully once the hop up was dialled in. Range was lacking but I'm estimating 160ft before the bb dropped. I would like to see 200ft consistently but range is secondary to reliability. On this note, the gun worked well, but the box mag began showing it's flaws:

1. Jamming. I had it jam on me twice. I think I have a solution - more to come.
2. The box retention system is crap, utter crap, when running with any weight in the box. Because of the mass in the box it will dislodge and hang on the spring feed tube and lower retention strap when I run. On this note, it also sags under weight and kinks the spring feed tube. Half the time I had to plant the bipod and hold the box in place for it to feed.

Solution: Bolt the box mag in place via 3 bolts and metal plate to clamp it in place. This combined with the straps (which won't end up doing much of anything) should eliminate this problem. The hole in the fabric box and plastic box also do not line up properly and this contributes to kinking the feed tube. The hole in the box will be enlarged and a grommet added, this should lower the tube and provide more efficient feeding.

On this note, I also bought a Condor Flashbang Pouch for externally mounting my battery on the front of the box mag. I much prefer this over mounting it on or in the box itself.

More to come on that.

But pics from the game!

On the defensive, falling back to our objective:

http://i1286.photobucket.com/albums/...psm6z1y1b3.jpg

http://i1286.photobucket.com/albums/...ps7eukdiro.jpg

On the offensive, M60's clearing a path!

http://i1286.photobucket.com/albums/...ps29f1cbsp.jpg

After the gun went down, trying to hold an area with my pistol while our squad pushed back, got taken out by a great grenade toss. Buddy filled a Thunder B with bb's and had it perfectly timed for an airburst right over my head haha.

http://i1286.photobucket.com/albums/...ps1o2u6sxx.jpg

Strange , I got my 7.62 link to fit into my A&K VN M-60 without modding it ? Is this because its a different type of M-60 ? You would think the feed trays would be the same size !

That could be it. I was looking at the A&K VN model on Saturday when another guy brought his out to the game. There are some distinct differences, this might be one. Or maybe my 7.62 rounds were not fully seated into the brass after having the powder removed.

I would be willing to bet it's the rounds lol.

Agreed on the 7.62 rounds.

Update:

Box Mag Modification

Before we can do anything to the box, we need to find the flaws in the feeding system.

After investigating, the box mag 'fabic' is the main source of the misfeeding. It is poorly designed in that it is too short. In order to fit the metal grommet, it needed to be placed below the re-enforced webbing. This means that the entire box and fabric need to be raised to prevent the entire weight of the box from resting on the feed tube itself and kinking the spring, jamming the box and putting extreme excess strain on the box motor.

This image shows how the box mag needs to sit to prevent misfeeding and allowing the feed tube flexibility. Notice how the top straps of the box mag are barely touching the rail, and realistically doing nothing. This means there is about a 3/4" travel between where the box SHOULD sit, and where it does sit per A&K's design.

http://i1286.photobucket.com/albums/...pszffw17be.jpg

So, how do we fix this?

I chose to modify both the box mag it'self and the fabric box.

I started with a ~1mm thick aluminium cover plate I had laying around that turned out to be the perfect size.

http://i1286.photobucket.com/albums/...psbewdaysb.jpg

http://i1286.photobucket.com/albums/...psvuut1wyz.jpg

http://i1286.photobucket.com/albums/...ps9ckoqo5x.jpg

After lining it up, I marked and drilled two 9mm (3/8") holes to fit two 8mm (5/16") bolts. This was followed by two 12mm (1/2") holes to align with the oval openings in the rail. Finally I used a stepped bit to drill a hole to match the large opening for the feed tube.

http://i1286.photobucket.com/albums/...pslmek6uga.jpg

http://i1286.photobucket.com/albums/...psypst5yqb.jpg

http://i1286.photobucket.com/albums/...psxuuhudv1.jpg

Then I put it in my vice, and used a hammer to bend the bottom 90 degrees after lining it up as it was too tall overall. This also provides a nice ledge for the plastic box to rest on.

After this I marked and cut two holes in the fabric box for the bolts to pass through and a third hole to bolt the metal bracket to the fabric through an existing 9mm hole in the middle of the bracket.

http://i1286.photobucket.com/albums/...psj0vdhgwp.jpg

After this I removed it all and hit it with some Krylon Olive Drab paint.

The final step was to fix the nuts to the box rail on the gun. I first filed all the paint off and left a crosshatch pattern in both the nuts and rail to promote adhesion, then used an industrial adhesive to glue the nuts in place and bolted it down. After I used JB Weld to encase the bolts and allow them to be fixed permanently for easy installation and removal of the fabric box.

http://i1286.photobucket.com/albums/...pspemvmddl.jpg

After this it was time to modify the box mag to lower the spot where the feed tube exits - the original location is a little too high, hence the weird notch in the box retention rail on the gun. With the box repositioned, it negates this.

Using a stepped bit I oversized the hole slightly. Then using some 1/8" Lexan I had laying around I cut a small piece and drilled a 3/8" hole to fit the tube. It was then glued in place with super glue, and painted flat black.

I apologise as I did not take a picture with the new hole drilled, but it was about 1/4" farther down. Maybe a little more, 5/16" possibly.

http://i1286.photobucket.com/albums/...psj8owld5p.jpg

http://i1286.photobucket.com/albums/...psoxe7kpfw.jpg

The feed tube now has a nice gentle curve to it while not flexing between the box mag and gun.

http://i1286.photobucket.com/albums/...psekv7vy6u.jpg

http://i1286.photobucket.com/albums/...pscourxk5c.jpg

Update:

New gears!

New parts arrived. Based on some maths, these gears will be 12.5% faster than the 18:1 stock gears. This means that with my settings at 90% ROF previously, I should take it down to 80%, and will then have a 2.5% higher ROF. EDIT: After field testing it appears the stock gears are 16:1

http://i1286.photobucket.com/albums/...psy1zmgwkf.png

http://i1286.photobucket.com/albums/...psyyxv3hzy.jpg

http://i1286.photobucket.com/albums/...psy1exokow.jpg

Ready to re-shim. During the process I discovered that I had never actually set my motor height correctly. The reason being is that the Lonex motor is a little longer (like 1/8") than the A&K motor. Even with the adjustment screw backed off fully, the alignment was out. So I removed it, and found a small washer (0.8mm ish) and it aligned it perfectly. The gearbox is of course much quieter now, and this may have contributed to the sheared teeth on the spur gear. In addition I glued down all the bearings to prevent them from working loose and interfering with the gears, which also could be a possible cause of the sheared teeth.

http://i1286.photobucket.com/albums/...pso7wtnkvu.jpg

So while I had the gun apart for the gearbox and just some maintenance on other items, I though, hey why not paint it... lol. Krylon Khaki, Olive Drab, and Brown - all from the camo series of paint.

Quite happy with the results...

http://i1286.photobucket.com/albums/...pswwi5rknm.jpg

http://i1286.photobucket.com/albums/...psx12keggk.jpg

Hey guys. Sometime this year I will be starting hydrographics. Makes for sick good quality camo, if your interested when I start it, msg me and I can paint your guns. Although you will need to completely disassemble your gun and take out anything and everything you don't want to risk water damage on (gearbox, battery, inner, etc)

Ok, time for an update.

Brought my beast out to a season opener in May with 100+ players. It performed beautifully. I'm very happy to say that the firepig scared the living sh*t out of Op-For on many occasions, and on a few my own team as I fired over their heads lol.


http://i1286.photobucket.com/albums/...psgmo1oxtp.jpg

The morning went very well, it was heavy per usual to lug around but worked flawlessly... however in the afternoon I kept killing batteries and having it jam on the anti-reversal latch meaning the gearbox had to be pulled in the spawn point to release it. At least that's what I though. As it turns out there was just more resistance so the motor would lock up, or catch on the anti-reversal latch, without a full battery charge. Why? Well I blew the two bearings on the Spur gear. From the looks of things, it still worked for a while after this happened haha. Oddly enough, the gun made no weird noises except making the same sounds you hear when batteries I was using were drained, (RPM dropping and then a locked up motor) which seemed logical at the time since I didn't get a chance to charge up some new batteries and figured they were not full.

Anyway pics...

The spur gear actually chewed up the side of the gearbox (minimal wear on the spur, props to Lonex!) Also the one piece cylinder I used (V1 Matrix one piece) had some slop, or the gearbox did, where the pins hold the cylinder head in place. This means that over 50,000 - 100,000 rounds that cylinder is being sucked back via the vacuum the piston makes and then hammered forward as the piston releases. So... it sheared off one of those posts, and this is what killed the gearbox unless I can fix that. The trigger switch also basically disintegrated...

On a positive note, despite everything that happened here, the only thing that made me purchase a new gear box is the peg that holds the cylinder head in place shearing off. The bearings, trigger, etc can all be replaced, and the gearbox would still work fine. So I will attempt to fix the gearbox and build a back up gearbox with it. More on that later...

http://i1286.photobucket.com/albums/...psdxtbl8ya.jpg

http://i1286.photobucket.com/albums/...psrivzf5l0.jpg

http://i1286.photobucket.com/albums/...ps1wattqy9.jpg

http://i1286.photobucket.com/albums/...psdoqnmysz.jpg

http://i1286.photobucket.com/albums/...psvu9vu9th.jpg

So, solutions...

1. Purchase a replacement gearbox. Unfortunately the Asian retailers were sold out, so I got gouged by Evike, even with the gearbox on sale lol. Cost over $100...

2. Matrix has a V2 one peice cylinder which looks like a better design. So I purchased that.

3. Replace bearings, at least on the Spur and Sector gears with bushings (not done yet)

4. Gut the gearbox and replace the internals with my upgraded ones.

5. Provide access to the anti-reversal latch for release prior to gun storage and in field if needed. The anti-reversal latch has caused me problems before and I'm sick of pulling the 4 screws to remove the gearbox. Especially when the box mag is attached and must be removed...

Pics... On the plus side shimming it went much faster the 4th or 5th time round lol.

http://i1286.photobucket.com/albums/...psj4ujvdmj.jpg

To solve the issue of the cylinder sliding back/forth I used a rubber 0-ring (not the one pictured as it was too big, but you get the idea) to take up the slack. There is zero movement in the cylinder now by hand. Any force will be cushioned by the o-ring and distributed to the front of the gearbox instead of the pins.

http://i1286.photobucket.com/albums/...psz4e6jx8t.jpg

To access the anti-reversal latch I measured/marked it then drilled a 1/4" hole in the side of the gun body. This was then filled with a long Phillips head screw with the shaft of the screw cut down to length to suit, then painted. Hardly noticeable and easily removed/reinstalled.

http://i1286.photobucket.com/albums/...psfhhqufvk.jpg

http://i1286.photobucket.com/albums/...psui6vbny6.jpg

http://i1286.photobucket.com/albums/...psjoworazc.jpg

This is a good write-up thread for anybody who is not only interested in the MK43 platform but some of the fixes/issues can be easily applied to A&K's other LMG lineup.

I would counsel you to just go full bushings on a setup like this since ROF/efficiency is not paramount.

Thanks Steve!

And yes I think that is what I will ultimately end up doing. Bushings throughout for reliability and simplicity.

A few updates...

1. The new gearbox was performing superbly until I started getting some weird ROF issues. Turned out the Lonex motor was toast. Popped the A&K motor that came with it back in, and it's been churning out plastic ever since! Oddly enough the new motor that came with the new gearbox was 'jammed'. I believe a foreign object is in there from the factory lol/shipping/storage. Not a big deal, just one less backup part.

2. At the most recent game I attended my motor set screw managed to work it'self loose and is somewhere on that field. I popped the gearbox out back at the HQ, a team mate had some hockey tape in his bag and we used trial an error to get the right thickness of tape then stuck it between the motor and motor cage, and she was back up running with a perfect motor position! The likely cause is I forgot to apply lock tight to the screw in the first place. The backup gearbox will need a new screw now...

On to the fun stuff...

A couple weeks ago a team mate and I were outside my place discussing a high speed/short stroked M4 build he is planning. I joked about 200 rps and a monster box feed system to accompany it. Then I got thinking, hey that's not a bad idea for the '60 (the feed system, not 200rps lol). He apparently had the same thought because he texted me that evening and we got the ball rolling.

Enter the Ironman (jump to 1:22 for the M60E3): https://www.youtube.com/watch?v=OKOt0nSpWEY

-and-

http://soldiersystems.net/2014/09/21...n-it-emulates/

http://soldiersystems.net/blog1/wp-c...er-430x256.jpg

Well that's really cool, but why bother for airsoft?

This argument is pretty solid for the M249, but my biggest gripe about the '60 is the offset weight of the box mag. It's a much more manoeuvrable and shoulder-able weapon without the box mag attached. Not to mention about 1Kg lighter.

So what are the objectives of the Airsoft Ironman Backpack build?

1. Provide increased ammunition capacity to the Gunner

2. Move the weight of ammunition from the gun & ammo pouches to a MOLLE or backback mounted system.

3. Make the system as lightweight and reliable as possible

4. Provide a quick detach system for CQB or other scenarios where the primary weapon system would be a hinderance

5. Incorporate the ability to feed M4 magazines directly to the M60 as is possible with the 249.

Great, how do you do it?

Well nothing is started yet as this will be a fall/winter/spring build but here is the gist:

A modified M60 box mag will provide the feed system and will be mated with a hard shell casing to allow increased storage capacity of ~6 000 rounds, maybe more, even 10 000

From there 1/4" (6mm) ID plastic tube will be fed to a QD plate which mates to a female QD plate bolted to the M60 box rail/support system. The M4 feed system from a 249 box mag will allow for QD of the feed system and a 4 post electrical harness will allow QD of the electronics.

In tandem to the 1/4" hose a 3/8" or 1/2" hose will carry 4 large gauge (probably 14g) wires to the backpack for power supply of the M60 and integration of the box mag, which will be controlled via automotive relay to isolate the circuit for a second battery. This should mean both the box and gun will run longer.

The plastic tubing will be concealed within a dummy feed chute system. The make up of this is still a grey area, likely high density foam, or hollow PVC. Adding too much weight here will completely negate the entire build.

This system may also open the door to a realistic looking polar star powered M60.

The hardest part of this will be the QD plates, but with the right fabrication this connection will operate smoothly.

Wow. I was about to give up and sell my a&k m60, but I check your post again and you've answered one of my problems again. Thanks for updating this thread!