Wednesday, 4 October 2017

Steely Slide Stopping Success

Is it wrong to be this exctited about a fairly small piece of technical innovation? If it is, I don't want to be right.

Around a year ago, I bought a second hand, run down KJW KP-08 with the hopes of fixing it. The four CO2 magazines that came with it had leaky valves, but most other things seemed to be in ok-ish working order. I put the gun and mags in a box and stored them for later. Once I now finally got around to replacing the valves and testing the magazines, I was faced with a new problem.

The old, original slide stop was so worn down that it would not stay put in the gun when shooting, and eventually decided to attempt evacuation at the most inopportune moment. The result (as best I can deduce and reconstruct the events) was that the slide slamming backwards hit the stop, and broke it in two.

At first I thought of just getting an original replacement part, but I've had my fill of pot metal parts lately, and decided to shop around a bit. That's when I came across this KF Airsoft steel slide stop for the Hi-Capa. I thought it brilliant, as I would not have to worry about it breaking again. Once it arrived, though, I was pleasantly surprised even further.

In addition to the stronger-than-original build material, the take-down pin is not a single piece, but a sleeved structure. What this allows is for the weight and force of the slide to rest on the sleeve, leaving the actual slide stop lever to rotate freely inside. In other words, you can have the take-down pin as tight as you want without it affecting how the stop itself functions. This is simply brilliant. I don't know who originally designed this, but it's damn marvelous!

As with all things airsoft, though, some modification was necessary.

As seen in the above image, there's a metal nub protruding from the inside of the stop, which would hit the feed lips and the side of the magazine, preventing proper seating and functioning. So, what else was there to do but break out the file set and get to work?

I filed down a bit, tested the fit and worked until nothing pushed against the magazine.

As a result, I ended up taking down the protruding nub entirely and shaving the backside of the retaining tab as well in order to secure proper fit.

I reassembled the gun and had a test fire. I'm now getting a very positive lock with this part. It's better, in fact, than the original one, and it cost just a few coins more than an OEM part!

It's (sadly) not everyday that you come across airsoft parts that surprise you this way. I'm pretty stoked this one did! If you have any similar experiences, please do share them below!

Wednesday, 12 July 2017

DIY P90 Sling Adapter

The biggest milsim event in Finland is coming up again, and just like last year, I'll be part of the HQ staff. If there was a lesson learned from last year, it's that you need very little gear when you're sitting in a tent most of the time. As a result, I thought I'd take my latest project, the P90, with me.

Alas, the gun has no sling point to speak of. After a bit of research, I found some examples of how you can sling the gun. As it happens, I had previously saved some webbing and plastic buckles from a pair of trousers I had to discard. A thought occurred.

These bits would be turned into a sling adapter in what was to become my first tactical gear sewing project. Luckily, we have a sewing machine handy.

The first bit was simple, just sew the female buckle onto the webbing.

Next, I sandwiched the D-ring between the buckle and the two layers of webbing. I would rather have used a plastic D-ring, but this was all I had available (and I was eager to get going).

It took a few tries to get right.

The flip side is not the prettiest, but it works.

The top side looks quite nice for a first ever project.

The next step was to thread the webbing through the hole on the underside of the gun and tighten it so that when the buckle is closed, the webbing is tight.

The loose end could be pushed into the same hole.

It's not exactly Tactical Tailor quality, but it's mine. I'm pretty happy with this little project. With a single point sling, the gun hangs under my arm at exactly the spot where my hand reaches the grip instinctively.

Do you have any sewing projects you've done? Please share in the comments below.

Thursday, 23 March 2017

Review: Odin Innovations M12 Sidewinder

This time we have something a bit different. This is the Odin Innovations M12 Sidewinder speedloader for STANAG (M4, M16 etc.) type magazines. It boasts to be the world's fastest speedloader, and after putting it through its paces, I have no reason to doubt that claim.

This piece of kit was kindly provided for review by At the time of writing, one unit retails for €49.90. The price might seem steep, but this thing is a far cry from the flimsy, see-through plastic things most of us are used to.

The speedloader comes packaged neatly and plainly. There's no excessive material, but still enough to keep the unit safe from most bumps and scratches.

Usage instructions are clearly printed on the side of the box, and highlight the main features of the speedloader. The most innovative thing about the Sidewinder is that the BB loading mechanism is equipped with a clutch, which will start slipping once the magazine is full, so you'll always know when you have a full mag, and overfilling the magazine is not possible.

The Sidewinder is capable of holding 1600 BBs when full, and the outer dimensions enable it to fit into a standard two magazine pouch with ease. Components are nylon fiber reinforced, which should guarantee a long service life. The speedloader seems very well made. All parts fit together neatly and there are no burrs left over from moulding. All in all the level of fit and finish is really high.

Operation is very straightforward. After filling the loader with BBs, you attach the magazine as you would into a gun. This is definitely a plus, since you don't have to hold the magazine in place, and there's no need to worry about spilling BBs everywhere. The crank handle swivels 180 degrees to allow easy stowage and fast operation. Then you simply turn the handle (or wind - on the side, punny) and once the magazine is full, you can release it with the push of a button.

Magazine compatibility seems good, at least with a limited set of testing. I had a PMAG, a metal Dboys M4 magazine and an ARES Amoeba mag. Each fit in well and stayed in place during loading. The ARES mag needed a bit of an extra push to seat all the way, but still worked as intended.

One possible thing to note with the Sidewinder is that it seems the last 6 or so BBs will not exit the loader despite how much you wind. This is something to keep in mind if you intend to load various magazines with different weight BBs.

My only gripe with the otherwise solid look and feel is the fact that most parts, especially the crank handle, are plastic. Nylon reinforced plastic is definitely strong, but the way it looks still makes me wonder about the durability. Odin Innovations are offering a one year guarantee for their product, so I'm fairly sure my worry completely unjustified. Personally, I'd prefer metal parts, but that's just my own preference.

If you find yourself needing a sturdy, big and quick speedloader to go with your STANAG magazines, I don't think you can really go wrong with the Sidewinder in any way.

As a final note, while the Sidewinder is only compatible with STANAG out of the box, there are 3D printed adapters available that allow you to use other magazines. I, however, have no experience with them, so I can't say how well they might work.

You can find the Odin Innovations M12 Sidewinder on the site here.

Wednesday, 14 September 2016

Fixer-upper Part 4: Classic Army P90

Here we are again. A broken gun up for grabs for cheap on a For Sale site. And grabbed it I did.

Patient: Classic Army Sportline P90
Symptoms: "Has had some electrical issues, been to a tech but stopped working again quite some time ago and has been unused since"

I've never owned a P90 before, but it has been on my get-one-some-day list for some time. This one is from the Classic Army Sportline series, meaning the externals are mostly plastic. Now, the real P90 is mostly plastic as well, so it did not bother me that much, even though usually I'm a stickler for realism in materials. Compared to a real P90 the only thing not of similar materials is the upper receiver. The outer barrel and flash hider are metal, as are the optics rails. Furthermore, metal uppers should fit right in if I ever want to get one.

The gun came with a Swiss Arms C-more style red dot (with a missing front clamp), two hicap mags, two NiMh batteries and a dumb charger. The internals had been upgraded to some degree, but the previous owner did not know much about them. In his words, he didn't know what had been done, the gun had been to a tech twice for electrical problems and now just would not fire at all.


It didn't take long to find out that the batteries had simply died. With a fresh 7.4 V LiPo this thing came alive, if only on full auto. Something was wrong with the semi function, and I could hear a rattling sound coming from the inside when the gun was tilted back and forth.

Externally everything seemed good apart from a small crack in the rear of the receiver. The two sides of the front grip also did not quite stay put due to a screw having lost it's threads. Nothing to hinder functionality, that is.

The P90 turned out to be exceptionally easy to disassemble. As you might know, my first gun was an AUG. That was very easy to gut, but this one was even better.

After popping the back plate, you see two screws. Take those out, remove the plate they held down, and the gearbox comes out.

The P90 uses a less common V6 gearbox, so replacements and spare parts are somewhat harder to come by than on your average AK or M4.

The upper receiver can also be removed simply by pressing a rectangular button on top of the receiver and sliding the whole assembly out. I could not help but fall in love with the design straight away.

The modularity was not limited to the externals. The gearbox comes easily apart as well, separating the motor cage, wiring and trigger switches into an assembly away from the main body. No wires to stop you from working, and you can test everything without inserting the GB into the gun.

The problem with the semi auto not working quickly became apparent once I peeked into the trigger switch assembly. A part had broken off from the trigger trolley (seen above still wedged below the trigger contacts). With the piece off, the trolley would simply skip over the trigger switch, not move at all and thus not engage the contacts.

The rattling I heard when tilting the gun was not an extremely short spring as I though at first (the gun chronoed just above 0.6 J), but rather the broken stem of the plastic spring guide sliding inside the spring.

The two main problems had been identified, and I got to work fixing them.


In addition to fixing what was broken, my plan also included swapping the plastic bushing for steel ones and re-shimming, fixing AOE, installing a MOSFET, and putting in a flat blade fuse and deans connectors. My plan was to build a CQB beast with a high ROF and moderate power.

Swapping out the broken spring guide seemed rather straightforward, as I quickly found a steel spring guide in my spares drawer. The V6 box takes V2 spring guides, which makes it easy to replace. Or so I thought.

A couple of test shots later the spring was compressed into the piston, which in turn was stuck in the rearward position. In case you've never done it, let me tell you that disassembling the gearbox again with this kind of a mine inside is just lovely. I managed to get it out without issue, luckily, only to have it get stuck again (because of course I had to try it again). It was pretty clear that the spring guide would not work here.

I scavenged another spring guide from an M4 parts box I had lying around, waiting to get assembled. It was otherwise similar, but the end was tapered and, more importantly, it had a diameter that was 0.21 millimetres smaller. The one fifth of a millimetre was all that was needed, the spring did not get stuck. The spring, as well as I, was free to move forward.

Swapping out the plastic bushings for steel ones was pretty straightforward, but they did sit quite low in the shell, and I had to use more shims than I've ever had to before. At some point I began to question whether or not I was doing something horrendously wrong, as the the combined thickness of the pile of shims on the spur gear crossed the 1 mm mark. It worked swimmingly, though, so that's tolerances for you.

Trying to fix the angle of engagement on the piston turned out to come with its own set of problems. The piston head was attached with a tiny nut sitting free inside the piston. I could unscrew the head with ease, but lacking a socket wrench for ants I could not put it back on. Who makes these things? I opted instead for an aluminium double sealed head I had lying around.

My problems with the spring guide had apparently resulted in some structural problems, since at some point during test firing the steel tooth broke off the piston. Luckily I had an old spare nylon piston with it's own plastic piston head that went in after a quick AOE fix, similar to the one pictured above.

My first attempt at fixing the trigger trolley consisted of glue and a several thin layers from a piece of paper towel. I figured a glass fibre style layer cake of material and bonding agent would result in a strong base which I could then file into shape. 

Too bad the plastic wasn't very glue friendly. The glue soaked paper held together fine, it just would not stick to the plastic hard enough to withstand the strikes delivered by the cut off lever. The same exact thing happened with various attempts made with super glue, epoxy and even chemical metal. This was one piece of engineering I was not exactly happy with. A thin piece of plastic subjected to repeated strike forces sounds exactly like a recipe for success.

Since the original plastic was a no-go, it was time to fabricate a stronger part. I chose a piece of sheet metal for the job with roughly the same thickness as the original plastic. After tracing out the shape of the trigger trolley, I cut it out, filed it down to size and rounded off any rough edges.

I drilled a few holes (with a 1.5mm drill bit) into the metal, filed down the original trigger trolley, drilled some holes into that as well and roughened up both surfaces, hoping the epoxy would finally bond well enough. I chose to make the holes canted every which way so that once the glue set, the pieces would not come off each other so easily.

To further address the issue, I cut down the trigger contacts so that the trolley would have more freedom to move up and down (the top piece is cut to shape above, the lower shows the original shape).

Everything was working pretty nicely apart from the fact I was getting triple and quadruple shot bursts on semi. The culprit in the end turned out to be my upgraded trigger trolley. The sheet metal was not as thick as the plastic, and thus the trolley was able to sit higher in its rails before disengaging. This in turn made it so that the cut off would not lift it out of place until the trigger was fully pressed down. I fixed this by epoxying another piece of the sheet metal onto the cut off and filed it to size. No more problems with semi auto! 

To round things off, I made a basic DIY MOSFET out of an IRLB3034 and some resistors. The middle prong is cut off and the negative lead is attached with a small bolt and nut to the back plate. Sturdier attachment, better flow of current.

Wiring up a MOSFET on a P90 can be done exactly like in the AUG, since the trigger assembly is the same. There's one switch and a pair of contacts for the semi, and another for full auto. It's only the movement of the trigger that decides whether the gun fires semi or full auto. On the AUG it's up to the shooter, on the P90 the fire selector limits the movement of the trigger.

All the extra bits and pieces fit in without issue and the gun was mechanically ready for service.

One final fix was to repair the cracked receiver. Since the material is ABS, you can forego glue and use pure acetone, as it melts ABS. My end result is a bit sloppy, but with an unhurried approach, slowly wicking the acetone into the crack, you can achieve a brilliant result. While mine isn't aesthetically as pleasing as it could, the upside is still that the plastic is again one single piece as it was when moulded, not two parts held together by an adhesive layer.

With an 11.1 V LiPo this little beast is pumping out 33 rounds per second at 0.92 J. Right on the money, if you ask me. Now I only need magazines that aren't hicaps and can still keep up with that.

Questions? Comments? Anything you'd add or like to know more of? I'd love to hear from you! 

Thursday, 18 August 2016

Pouch Painting

If you've ever bought gear from more than one manufacturer, you've most likely been there: Colours don't match. Olive drab especially seems to be a complete no man's land when it comes to colour coordination. They're all supposedly the same colour, but when you place them next to each other, you will certainly notice they're not.

You can always go out in your non-matched set, or grab a can of spray paint and go to work. Here's a quick primer (yes I went there) on how to get your garb to match.

The picture above shows quite clearly just how different the concept of olive drab can be. The RRV replica underneath is from Miltec, and the various pouches are from Pantac, TMC, Condor and from an unbranded Chinese manufacturer.

Painting nylon is fairly straightforward, just apply several thin layers as you would do with any other spray paint project. The de facto brand that people enjoy using is Krylon for its consistency but I went with a camo colour series from my local car parts etc. retailer, Motonet.

Here's a great example of "do as I say, not as I do". I went a bit overboard with the spraying on this TMC radio pouch, and you can see the otherwise matte paint is starting to glisten on the lip of the pouch. Otherwise the result is pretty good. You can clearly see the difference between the painted part and the so far unpainted fastener on the top right. Do note that the paint interferes with velcro to some extent, so try to avoid spraying large quantities over such surfaces if you want to retain the stickiness.

Some parts, such as the crease on the pouch above can be a bit problematic if you want an even coat. You can, however, always spray and then rub the paint in with your fingers, for example.

You can also use gloves while doing it. Assuming you're not too dumb and/or excited to remember such things, of course.

Really getting there after only a short while. I'm sure the father-in-law doesn't mind spray paint on his lawn.

The end result after three(ish) light coats. The AK pouches were left unpainted to be used as reference. I left the paint to cure overnight before using the pouches.

Do you have experiences in painting your gear (or guns)? Let me know in the comments!