Airsoft Hacks

A common problem here in the south of Ireland that makes us envy our Northern brethren airsofters is the lack of pyrotechnics which we can employ during an airsoft skirmish. A few flashbangs and a bit of smoke could really add to the combat atmosphere, especially for milsim events. Unfortunately under Irish law these devices are classed as pyrotechnics and require a licence and permission to import and use. Obtaining a licence for their use is not a simple matter either, even when importing pyrotechnics there is a raft of paperwork which must be filled out and you must specify the date, time and location in which the devices will be used, not exactly useful for airsoft use.

About a year back I created a small ventilated metal cylinder, about the approximate size of a hand grenade, into which you could place smoke pellets which can be bought in Joke Shops and Novelty Stores across Ireland. This worked moderately OK in a CQB environment, but ignition was always a problem. Even fuses are a restricted item in Ireland!! I had tried several experiments making homemade fuses from the sulphur scraped from match heads, some string and super glue, it never really worked particularly well and was far too time consuming to ever be a realistic option.

Sparked by a recent thread on boards.ie about legal options for smoke grenades I decided to do some searching on ebay. I was initially looking for industrial grade smoke pellets which I could build a new holder around and I came across these ph Smoke Matches, could these be a potential solution to the ignition problem? They appeared to light just like matches and had an extended head which would give off smoke when burned.

These arrived today and I immediately decided to give them a test, lighting one by hand at first, I didn’t expect much from a single match but had hoped that perhaps lighting several would provide a decent amount of smoke. A small amount of smoke was produced which was quickly blown away by the moderately light wind which is blowing in my back garden.

I then decided to try a whole box (12) at once. This gave off a good deal more smoke but still not enough to ever be considered a really viable alternative to pyrotechnic smoke grenades. Perhaps in an indoor CQB environment they might prove slightly more useful perhaps with using several boxes of them simultaneously, but care must still be taken as when lighting several together, there is quite a large flame which burns for several seconds.

I’ll let the video speak for itself on how they looked:

So that’s it for those, back to the drawing board for a legal alternative to smoke grenades in Ireland.

Hands up if you’ve ever wondered about the difference in different weights of BBs? Accuracy, range, wind resistance? Well, here’s another factor which I never considered until recently. I read a post on arniesairsoft.co.uk in which the poster mentioned that using heavier bb’s could potentially increase the power output (i.e. Joules). Essentially what it boils down to is that heavier weight bb’s stay in the barrel longer, therefore get more time to accelerate than lighter ones.

To test this theory, I grabbed my favourite AEG (TM P90), which fires at a fairly consistent .95-.98J and some Excel brand 0.2g and 0.25g BBs, testing with the different weights gave the results below:

Theory smashed? Yea, that’s what I thought too, I decided to test it out with another device, conveniently I had my KSC G18c to hand which I loaded up with some gas and BBs, results are below:

Haha! That theory seems it might have some grounding in truth, well, to be a bit more sure, I tested with 2 more pistols which I had handy, a Meister Glock 17 GBB and a KSC Glock 19 GBB, yes I know, all Glocks, you either love them or you hate them and in my case it’s definitely the former, but don’t judge me on that, I own several other pistols which aren’t Glocks too :).

The Meister Glock 17 achieved power outputs at:

And the KSC Glock 19:

So, what exactly is going on here? Well, the key difference is that the P90’s barrel is 247mm long, whereas the pistol barrels are only about 100mm long. The fact that the p90 has the same output power with both the .20’s and .25’s shows that the physical size of the BB is not playing a part in the extra power output, infact I measured a sample of both .20g and .25g BBs and found them all to be the same size (5.88-5.90mm).

The extra length of the P90 barrel in comparison to the pistol barrel gives the BB ample time to accelerate using the energy of the gas behind it (in this case, the air which is pushed by the AEG’s piston), however the pistol having such a short barrel causes much of the energy (in the form of gas) to be expelled out the end of the barrel after the BB has already exited the barrel. Using a heavier weight BB means that the BB spends longer in the barrel of the pistol and has more time to be accelerated by the expanding gas behind it, thus a greater amount of energy is transferred from the gas to the BB.

So not only do .25g BBs have greater resistance to wind, they actually make more efficient use of the energy expelled by the GBB, but in the case of the P90 with a barrel of 247mm, it made no difference. I’ll conduct some further tests on AEG’s with different barrel lengths, but I’m fairly sure that anything with a barrel of around 200mm or more will not see any difference in power output with different BB weights.

It is also important to remember that here in Ireland, the legal limit for any airsoft device’s output power is 1 Joule, using 0.25g BBs with a device which fires at 0.99J on 0.20g BBs may actually increase it’s power to above 1 Joule, care must be taken to ensure that you are compliant with the law at all times.

Thoughts/Comments/Suggestions? Feel free to click the comment button below.

*Update:

I repaired my Cyma Glock 18 AEP last night and re-wired it with an external battery, so this morning I decided to conduct a few more tests, below are the results using .20g and .25g BBs as above.

As you can see, there is no noticeable increase as with the GBBs, infact with the .25g BBs in the AEP, the power output decreases. Theory busted? Well, no, not really, the Glock AEP has a much smaller gearbox than an AEG and a very small piston/cylinder to compress air in, so in this case, the volume of air in the cylinder matches the volume of air required to propel a .20g BB efficiently down the relatively small 100mm barrel. Were this a full sized AEG gearbox with a 100mm barrel, then quite likely the expected results of the energy level increasing would be seen.

I’ll be conducting a few more tests with this theory to try and get the most conclusive results possible, so check back for more updates soon.

I recently had the opportunity to strip and upgrade a TM Sig 552 belonging to a fellow airsofter so i decided to take some pictures while i was at it and post them here with his kind permission.

Firstly, to start off here is the Sig 552 itself with the top part of the foregrip removed, and also the battery tray has been removed:

Remove the motor plate from the bottom of the grip by unscrewing the two screws either side, you can leave the allen key in the middle alone, this is the motor adjustment plate and unless your motor isn’t meshing correctly with the bevel gear, doesnt need to be touched.

Once that’s done, unhook the wires from the motor itself and remove the motor, watch out for the small metal disc on the bottom of the motor which will no doubt fall off and can sometimes stick to the side of the motor due to magnetism

next, have a look into the grip and you can see two screws which hold the grip onto the gearbox (brass here, but some aegs they are painted black and very hard to see)

Note the two motor wires go through the same hole in the grip

Fold the stock and remove the screw at the top pictured here

Then remove the two screws on either side of the body just behind the selector switch

the entire stock can then be slid straight off

On the underside of the selector switches is a small allen head grub screw, unscrew these halfway (so you dont lose them) and remove the selectors

underneath the selector is another piece which attaches to the selector gear assembly on the gearbox, unscrew these and lift them off, note that the one on the left hand side has a small spring and plastic piece which click into place when you turn the selector, be careful not to lose these. Also the one on the right hand side has a longer screw

Now remove the screw inside the mag well

And the two screws on either side (at this point you should have removed the bottom half of the foregrip too)

Next remove the screw just forward of the mag well

at this point you should be able to lift the upper half of the body forward and up away from the bottom half, note that it will be necessary also to remove the cable ties holding the fuse holder in place

The gearbox can now be lifted out of the rest of the body

note the position of the gears outside the gearbox which are controlled by the selector switch

right side

and left side

The larger of the gears will simply lift straight out, the small one on either side requires a screw to be removed on the left side and then slides out

Once you remove the gears on both sides, the black plastic piece underneath needs to be remove on the right hand side, simply pull it slightly down towards the trigger and it will unclip, underneath this there is also a small metal piece which sits partially inside the gearbox to block the trigger, unfortunately i havent got a photo of it, but you’ll know it when you see it

This is the positioning of the selector plate and other components, you dont need to remove anything here, this is just for reference

Inside the gearbox with all the original parts installed

Systema High Speed gears, 1 Joule spring and metal bushings installed, also gears were re-shimmed

Now just stick everything back together in reverse order

The 9.6v custom battery being test fitted without the top half of the foregrip, note the position of the connector and the orientation of the battery with particular reference to the side which only has 2 cells

When the battery is correctly position as above, the only modification that needs to be made to the inside of the foregrip is to dremel away a little bit of the protruding area of one of the nuts/screws that hold the side rail on

and your done, this particular AEG now runs at a nice 19-20 rounds per second and has a nice crisp trigger response, havent had the opportunity to chrono it yet but with a systema 1J spring i would expect in the region of 300-300

As I mentioned in my last post, I decided to do some testing on the difference in rate of fire with a stock DBoys Full Metal M4A1 and different motors and battery voltages. At the time I had available to me the stock motor that came installed in the M4, a Tokyo Marui EG700 motor and a Systema Turbo motor. Batteries used for testing were the standard 8.4v mini battery which the M4 came with and an Intellect 1400Mah 9.6v battery.

Onto the tests..

To calculate the average rounds per second, I used my laptop with a standard pc microphone and used Audacity to record the sound of the gun firing. Each wave peak recorded and graphed by audacity can be counted as a single shot. For each test, I fired one 2 second burst followed by a 3 second burst.

From the sound wave produced in audacity, I then counted the number of peaks in a given second. I took 3 seperate seconds and calculated the average based on those. Below is a table of the results achieved. Note that there is no figure for the Systema Turbo motor running on the 8.4v battery, the cheap batteries that come free with clone AEGs do not appear to be powerful enough to push this motor with a 1 Joule (or close to it) spring installed. However I have tested with a good quality 8.4v battery and it ran quite well, although it was at a skirmish so I was unable to record the rate of fire at the time.

And while we’re at it… here’s a nice shiny graph of the whole lot:

Motor and Battery Rate of Fire Comparison

It should also be noted that the Systema Turbo motor is a very heavy drain on a battery, the Intellect 1400Mah battery I used lasts less than a thousand rounds, so you pay a price for that kind of rate of fire.

Interestingly the stock Dboys motor and the TM EG700 motor performed exactly the same, running with a 9.6v, the TM motor did average 14 rounds per second as opposed to the stock motor’s 13.67, however this is not a significant enough difference to be conclusive. Physically the two motors are identical and performance wise they also appear to be the same.

There’s not much more to say on the matter really, the results above say everything I could, any questions or comments though, feel free to click the comment button below.

Oh and while we’re here, here’s some nice pictures of the various wave forms recorded in Audacity:

8.4v Stock Motor

8.4v TM EG700 Motor

9.6v Stock Motor

9.6v TM EG700 Motor

9.6v Systema Motor

Well, it’s been a few weeks since I posted anything, but just wanted to put up a post of what to expect on here soon…

• Cyma Glock 18 Review

As promised in my first post on this blog, I will eventually get around to posting a review of the Cyma Glock, this is a nice little AEP which costs about half the price of it’s TM counterpart.

• Cyma Glock External Battery Install

The main disadvantage of the Cyma Glock AEP (and alot of other AEPs) is the limited space for a battery, hence the reason why they only have a 7.2v mini battery installed, so instead I decided to custom make a lanyard which clips onto the bottom of the handgrip and can be run to a belt/vest/pocket to utilise a larger external battery. So far I’ve briefly tested this and installed some wiring but it hasn’t quite performed as expected, right now it looks like the wiring is causing the problem, so this will have to be re-wired with some higher quality wire, although this is difficult given the limited space inside the pistol.

• Molybdenum Disulphide Gearbox Mod

Moly…. WTF? Indeed, I read about this on a thread over at arnie’s airsoft, it’s commonly known as dry lube, the basic concept is that it acts similarly to a teflon coating on the gears allowing the gearbox to perform very well without wet grease becoming dirty and clogging up the gears. I’ve been waiting about 6 weeks now for a can of this stuff to be delivered to me and it finally arrived today. I hoped to test it in my Cyma mp5-J, looks like I’ll have to wait another couple of weeks to test it out (see below), but when I do, I’ll post a full review here and an update after several thousand rounds have been run through it.

• ACM “Silent” Piston Head

Picked one of these up on rsov.com with an order a few weeks back, haven’t yet decided which AEG to test it in, but as soon as I do I’ll be posting a review along with audio comparisons of noise output from the gearbox.

 Right now, I’m limited on time, this coming Wednesday (18th) I’m flying to Barcelona to spend a month travelling by rail around Europe, I’ll aim to check out at least one european airsoft site while I’m there and will post here any (airsoft related) experiences I have over there.

I aim to post the Glock review before I go anyway, and the rest as soon as I can. I’ve a few other ideas in mind and will be updating this blog as those ideas come to fruition.

Slán go foill.

K

So way back in the day when I bought my first airsoft AEG (A little less than a year ago now, since the law in Ireland has only recently changed), I bought a Cyma Mp5-J from actionhobbys, I think it cost me around €130 at the time, which is an average price for a clone. Service from actionhobbys was very good, I think I was one of their first customer’s from Ireland and they were very helpful in looking up shipping costs for me. Anyway, being my first AEG, I loved it, but even now that I’ve bought more airsoft guns and fondled plenty of other people’s, it is still a great gun for the price. It is well made, sturdy and I’ve yet to have any major problems with it. It fires at around 260fps with 0.2g bb’s, which is decent enough.

Since it didn’t cost too much, and I’m currently using a TM P90 as my main aeg, the mp5 has become my project gun. I think I must have stripped and rebuilt the gearbox at least 20-30 times now, and that’s no exaggeration. The first of my many upgrades on this gun was a Systema 6.04 tightbore barrel, one of the downsides of the Cyma is that the hopup unit is a little weird and non-standard, so a bit of dremel’ing was involved to make it fit, but this wasn’t too hard to do, taking about an hour or so to complete. All went well and I brought it to my next skirmish the following weekend at hrta, before the first games of the day, I was out in the firing range and had my first experience of “THAT horrible grinding noise”, yup I’d stripped a gear, I cursed the gun and ended up using a Galaxy mp5k for the day which was a rental gun, I also had my HFC m190 pistol at this stage, but not the P90.

Eager to get my mp5 back up and running, I ordered a Guarder Full Tune Kit from ehobbyasia. I had a few problems getting the FTK installed in the Cyma gearbox, it would often jam up after several shots or jam before even firing one shot. After several days of frustrated rebuilding, I eventually found the problem to be the Guarder upgraded piston, I swapped out the piston with the original Cyma one in the gearbox and had the mp5 up and running quite well for a while with the stock spring and piston and the rest of the gearbox upgraded. At this stage, I’d had my p90 a few weeks and the mp5 became a little less used, it was under-powered and nowhere near as fast as the p90.

About two weeks ago I decided it was time to give myself a reason to use the mp5 again. I went ahead and ordered a PDI 120 spring, which is good for 300-330fps and also a Systema Turbo motor. I’d read some information on the Systema Magnum and Turbo motors, they offer high speed and high torque in the one motor, ordinarily it’s a choice between one or the other. They are pricey motors at approx USD$80 without shipping, but I figured why not? While I was browsing, I decided I’d throw a 9.6v battery into the order for good luck, I was still using the 8.4v that came with it and needed a new battery anyway.

Last Friday I installed the new motor and spring with the rest of gearbox as it was, holy shit are those motors fast. With the stock motor and spring in my mp5, I was getting around 12/13 rounds per second, with the new motor and a 1 Joule spring it was pumping out an amazing 24 rounds per second, pretty damn fast I have to say.

After my initial excitement about the rate of fire, I started actually listening to the gearbox between shots, it didn’t sound good at all, I knew what the problem was at once, the stock piston just couldn’t handle the upgraded power and speed, I left the piston in and decided to go ahead and bring it to a skirmish at hrta the next day. After some initial showing off of the rate of fire (people have commented on the speed of my p90 at 17rps), I attempted to chrono the mp5, unfortunately the semi-auto has never really worked all that well since I got it and no longer works at all, so firing a single shot is a matter of being very quick on the trigger, it was impossible to get a proper reading. I also noticed after my showing off that it didn’t seem to be firing very well at all and the gearbox noise had gotten worse, I left it in my bag knowing I would have to rebuild it when I got home.

Got around to opening the gearbox tonight and it was not a pretty sight at all. Eleven (yes, that’s right 11) teeth are stripped off the piston, and the next one is not looking too good either.

The sector gear didn’t look too good either, a few of the teeth (around 11 I would guess ) had the gaps in between them filled in with a collection of the plastic from the piston and the grease in the gearbox.

I spent a few mins cleaning the gunk out from between the gear’s teeth and grabbed the upgraded piston that came with the full tune kit, I had decided I would dremel the piston if necessary to fit it in, the problem appeared to be caused by the rails not sitting correctly in the gearbox, I had a look and it seemed there was a bit of plastic which had been badly formed on one side of the piston rails, although it was barely visible to the naked eye, I could feel it if I put the piston into the rails inside the gearbox. A few rubs with a sharp screwdriver and the extra bit of plastic was gone, the piston now slid freely inside the gearbox.

So fast forward a half hour and I had the gearbox rebuilt, re-greased, the PDI 120 spring installed and the gearbox mounted back into the lower receiver with the motor installed. Now where the hell did I leave that bloody battery…

They say a picture paints a thousand words, so below is a video of it firing, at this stage I was just testing so just had the gearbox mounted in the lower receiver:

As you can see, it’s pretty fast, with the new piston in, it’s getting 20 rounds per second now, still not too bad at all, the reason it has slowed down is because now all the piston teeth are intact, it’s not releasing the piston early anymore, if I was to remove a tooth or two on the piston, the rate of fire would increase again, probably back up to around the rof it was with the original (damaged) piston in place.So there you have it,

Cyma mp5-j = Great clone/starter gun

Systema Turbo Motor = Bloody fast motor

Cyma mp5-j + Turbo motor = CQB Support Weapon

Now I just have to find a box-mag for an mp5.

Oh and incase anyone asks, yes the original mag can handle the higher rof just fine, no jams or misfeeds with it yet. Below is a video of it firing at a target net.