Some thoughts on upgrading Cybergun SA sig 552s

[Jackarutu]

I find myself looking at repairing/upgrading a ton (225 so far) of sig 522s. As-far-as I can tell the type I’m looking at upgrading was produced for Cybergun SA.

Over in the review section Rotting posted a really nice review of the one sold in Canada with a clear plastic receiver. However, if I’ve done my homework diligently then I believe Cybergun SA packages several different configurations of these sig 552 (clones). In the US market they are sometimes misleadingly advertised as JG SIG 552 AEG (Metal gearbox) and sig 552 softair/ JG Jin Gong AEG. However, I believe that Jing Gong didn’t actual assemble these. Perhaps some of the parts were produced at the Jing Gong factory but I think these $130.00-$70.00 clones are actually assembled by a third party. When I called Cybergun SA (http://www.cybergun.com/) asking about repair parts they pointed me towards Palco (http://www.palcosports.com/index.cfm). I haven’t contacted Palco yet but from what I can read on their web site they offer three different types of sig 552s and none of them seem to be what I have. How do I know mine came from Cybergun SA? Because most of them have a sticker on them saying: “Manufactured by Cybergun SA Made in China.”

Palco lists on their site:

Sig Sauer 556- Full Metal Body- Metal Gears- Metal Gear Box- Full/Semi Auto- Adjustable Spin-up Palco Sports Part #: 28907;
Sig Sauer S-552 - Clear - Metal Gears & gear Box - Adjustable Spin Up - AEG Palco Sports Part #: 28903;
Sig Sauer s-552 AEG Machine Gun - Metal Gears/Gearbox - Tactical rails - Folding Stock - Black - Box - Full/ Semi Auto - Adjustable Spin-up Palco Sports Part #: 28902

I think the part number 28903 is the one sold in Canada as reviewed by Rotting.

Edit: I think I sorted out what I'm actually working on as the "Cyber Gun SoftAir" for the European market sold as Swiss Arms SIG 552 Commando AEG 1J item: 280902.

Tokyo Marui makes a Sig 552 and so does Jing Gong and ICS offers one with a metal receiver but will the parts all interchange is the question.

I think many here on the AirSoft Canada forum know about the HurricanE - SIG 552 Metal Body but these seem to sell for around $190.00 and I haven’t really found a good source in the US yet. And then there is the Marui Parts Showcase located in Huntington Beach, CA, United States that sells the ABS plastic lower receiver for the Marui Sig 552 for around $30.00.

Where-as most of the sig 552s I have all have crushed/broken tabs on the front end of the lower receiver I must decide to either repair the ABS (a really messy and time consuming job mucking about with glues and trying to patch them up) or replace the lower receiver. I might do a few with the HurricanE receiver but at $180.00 that seems a little high to me but others may have different thought on this. Or I can use the Marui receiver at the much more reasonable price of around $30.00 and hope that they are made of better ABS then the ones I have and will hold up better. At this time I’m not really sure why so many of these are broken (was it defective inject modeling technique or rough handling during assemble or a design defect and they failed during testing because they couldn’t take the pounding to the gearbox hammering back and forth, or perhaps the shipping container was dropped off the boat to the dock at a very fast pace?)

Edit: a customer just dropped off a TM SIG 552 and on inspection I find the mounting tab on the front of the lower reciever where the screw passes thru to bolt it to the barrel assemble is broken and crushed on it also. I still have no idea why 90% of the ones I've looked at (around 200 at this time) have this damage?

The best possible option would be for someone to read this and report back that ICS is now offering their metal receiver in North America at a reasonable price (the ICS receiver is on their web site http://www.icsbb.com/ with a part number however, their email doesn’t see to work). Also if one looks around they can find on the ICS web site some interesting views of the sig dissembled.

http://www.icsbb.com/eicsbb/prd_mp1.asp?bignum=13 shows the ICs sig 552 parts and their respective numbers.

Enough about the external for now let’s move on to the internals. Basically what we have here is a version 3 gearbox. So what to do next? Looking over many US Airsoft suppliers I didn’t find one that lists any internal parts specifically for a sig 552. I can’t say I checked ever online sales in the US but I did check many of the major ones.

Edit: When I say that supply is a problem I'm speaking on the local level. Many manufactures do make parts specific for the Sig 552 series of weapons ike Modify and Systema but getting dealers in the US to carry them is a different story.
Some observations:

Here is a picture comparing the power spring to a OEM JG M4 and a Modify M110.



The spring at the top is a Modify M110 the spring in the middle is a standard OEM JG M4/M16 spring and the one at the bottom is the sig 552 power spring from the sig 552s I have been working on.

My first thought is that I will upgrade some of these sig 552s using the Modify M110 spring and a Modify metal spring guide with bearing to replace the plastic spring guide. Since I have never liked using the stock plug that holds the stock spring to the stock piston head I will be replacing these with a Modify Piston head with bearing. And since I’ve gone this far I might as well replace the stock piston with a Modify piston. However, I actually don’t see anything wrong with reusing the stock piston if it isn’t damaged.

Several of these sig 552s came in with crushed pistons and cylinders that were scratch and scored on the inside so bad I had to replace the cylinder. In those cases I used the Modify M4 cylinder kit (which comes with cylinder, piston, piston head and cylinder head). I had a few cases where the gearbox was making a strange sound and when opened I found some slight damage to the piston teeth. In those cases I wasn’t doing upgrades but rather just repair so I used some JG OEM M4/M16 Springs and pistons I had laying around from other upgrades I’ve done to M4/M16s.



Now I know some may think I’m trying to push Modify but to each his or her own. I’m comfortable with modify but others are free to use whatever they feel is working for them. At some point after these weapons have been put through some field testing I hope to report back to this post and update it with any results I might observe. So if the Modify parts don’t hold up well I’ll try to report that.

I also don’t necessarily suggest that everyone drop in a $90.00 Modify Smooth gear set for upgrading these sig 552s The stock XYT gears seem to me to be okay and just replacing the plastic bushing and re-shimming would go a long way towards a nice upgrade in my opinion and I’m sure I will do many of these in just that fashion. The only thing I didn’t like about the XYT gears is the fact the pinion and selector have loose sleeves on them but still in all they are okay.

Next I’m concerned with the air nozzle. Again here we have the case where there doesn’t seem to be any suppliers offering air nozzles specifically for the sig 552 and even if they did are all sigs made the same? In my case I measured the length and compared to an JG OEM stock M4/M16 air nozzle. It seems to me what’s important here is how the hop up fits to the lower receiver and how the gear box fits to the lower reciever.

Comparing the hop ups I have with the picture on the ICS web site it seems the same except ICS shows a spring that is not on the sig 522s I have. I think for the ICS sig 552 the springs works like the spring on a CA36 the pushes the hop up firmly into the air nozzle. Without actually having the lower receiver and air nozzle and hop up from all the different manufactors it’s hard to say at this time if all these are interchangeable. Perhaps someone reading this will know and respond to help add to this post.

Systema has an air nozzle that they list as being used on the SG 550 and SG 551 part number ZS-04-30. If anyone has one perhaps they will measure it and report back if it is also 2.18 mms long? In any even I think that even thou I’m using a cylinder sets for a M4 to upgrade these sig 552 gearboxs that the air nozzle that comes with the kit is too short. I think 0.007 mm difference is enough to cause feeding problems and a bad air seal but hope for input from others on their thoughts.

I any event here is a couple of picture of comparing the air nozzle to a JG OEM M4 air nozzle.

Edit: Modify's part number for their SIG 552's air nozzle is GB-08-07 but I haven't found a US dealer that carry's them yet. However, that doesn't mean its not available somewhere in the US at this time and I just haven't stumble accoss it yet.

First the M4 air nozzle.



and the Cybergun sig 552 air nozzle



The last thing I’m doing to upgrade these sig 552s is to rewire them using fine strand silicone wire. I also will be removing the fuse. These weapons will be used for swat training and the participants are intelligent enough to understand that if when they pull the trigger and nothing happens how to make sure the battery is connected correctly and if it still doesn’t fire that the weapons needs to be returned for maintenance instead of holding the trigger until they fry the wiring. Fuses are just one more place to cause the wiring to get high resistance or cause broken wires in the field or cause problems with trying to assemble the fore grip on weapons with tight battery space. In my experience the cheap fuses holder that come with AEGs are a pain in the backside. The original wiring is shown on the right of the photo.



That’s all I have on this subject for now. I hope to hear others thoughts and experience on what else might be useful on up grading these sig 552s and or keeping them repaired.

[Rotting]

First wording error I noticed was "Modify M110". Modify makes the S-Series springs, not the M-series springs. Not sure if you're speaking of the Mad Bull M-series springs now or the Modify S-Series springs now. Obviously the S110 and the M110 are different. If you're referring to the S110, I wouldn't recommend it. The S110 may put un-wanted stress on the rest of the gearbox. However if it is properly upgraded, it can handle it just fine.

Another thing worth mentioning is that the M4 uses a Type-1 ported cylinder, the SiG 552 uses a Type-2. The power of the Gods says match your cylinder to barrel length for optimal results, since you said you used a M4 cylinder set.

From what I understand, the ICS SiG552 Metal Body is not compatible with the TM (and TM clone) SiG552 models. I'm not sure why, that's just what I know. Had a brief conversation with someone regarding it. Something about how the bolt works doesn't agree with it since the mechbox is different or some crap. Be wary. On another note, the FUCK? $190 for a metal body? Even if that's in US, jesus that's cheap.

The gears are actually quite durable. I like to be an asshole with my parts, make sure they're worth the money I just dropped on them, so I like to throw them around, bang them, put some stress on them entirely. With the default ones from the "Canadian Legal" CyberGun SiG552, the gears have no chipped teeth, no chips, no dents, no malformations, nothing.

For your concern regarding the air nozzle for a SiG551 and SiG550 being the same as a SiG552, I'd suggest PMing "Disco_Dante". He owns a SiG551 and a SiG552. He'd be able to give you confirmation if they are the same or not. From what I gather, though, the only thing different internally about the SiG551 from a SiG552 is the cylinder and barrel. I'd expect everything else to be the same (minus the spring).

Re-using the stock piston because it has no visible damage isn't a reason to use it in my books. If you do plan to use a stronger spring, that piston may very well just get ripped apart. Only has one metal tooth, and you're going to want full-metal teeth to optimize the life-span of your piston (In this case, also make sure the gears are good quality, which you've already stated you have done anyway, since otherwise the piston will just fuck your gears' shit right up).

ICS SiG552s are different from TM clone SiG552s. It's almost like they said "Fuck this shit" and remade their own insides special to ICS. I'd suggest interviewing someone who owns an ICS552 and get some pictures regarding the areas of conflict, otherwise you may get a mess of problems. Just my two cents on that one...

Oh, and also. That stupid little tab on the underside of the front lower reciever? Breaks due to the screw being too tight at times. Creates unreasonable amount of pressure, over time and use, it slowly begins to crack, then ulimately it breaks off. Another reason is that the screw isn't deep enough in, and when putting the handguards back on, people assume that the handguards just need some shoving to get it in place, and this isn't the case. This smacks up the screw for one, the screw dispenses energy into the tab causing it to get weaker every hit it takes, rinse and repeat a bunch of times, and you have a potential shatter-point and you're minus a tab. Strongerly suggest to anyone who uses a SiG552 with a plastic reciever to gently bring the handguards in, and if there's resistance, take them off again and turn the screw 1/4 of a rotation, try the handguards again, and if it still doesn't work, rinse and repeat until the handguards are securly in place. Once they are in place, take off the handguards, turn the screw another 1/4 of the way for extra security so that the energy from any force on the handguards isn't being dispensed to the screw as well, and therefore the tab, causing slow degeneration of the strength of the tab.



If some of that didn't make sense, it's 11:50pm here and I've been reading a physiology book for the past 3 hours. I'm tired.

[Jackarutu]

Rotting,

Yes I did type M120 when I meant to type S110. According to Modify the S110 is one step (two steps up, corrected by Reckless thank you) up from the S90 and the S90 is equal to the stock spring in most M4/M16 gear boxes and I did show a picture showing all three springs side by side. However, it escapes me why you would say the S110 is too much spring for the SIG 552?

I don’t follow you about the Modify M4 cylinder not being correct for use on the Sig 552. When I lay the two cylinders side by side the port is in the same place. If this is wrong then Modify has been packaging some wrong cylinders in their kits. I have about 30 of them in stock and they all seem the same to me so if they messed up they did it on a complete lot of them.

Now, in relation to this subject the Cybergun Sig 522 inner barrel measures 10 16/32 inches long which would come in at around 277.8125mm.
Illusion listed that the Prometheus Stainless Hard Cylinder (D) 251 - 300mm (9.8818897637902 - 11.81102362206 inches) would fall in the range that would fit it and as you can see “D” would be the fourth port position.
Systema N-B Cylinder Type-2 ( ZS-04-18 ) MP5A4 / A5 / SD5 / SD6 / MC51.
Illusion goes on to say that Toko Muriu uses a port that is
3/5 of the length of the cylinder for - MC51 / G3 SAS / AK Beita Spetsnaz / MP5A4 / MP5A5 / MP5 RAS / MP5SD5 / MP5SD6 / MP5-J / P90 / P90 TR / Sig552


Also about the lower receiver tab being broken on so many of these I just got in a TM lower receiver brand new and it was cracked into the screw hole before I even opened it up.

You might be interested to note that from looking at the ICS parts guide I notice the hop-up come with a spring like the M249 uses to keep pressure on the hop-up against the gear box and that makes me thing the ICS hop-up doesn’t screw down to the mag well plate like the cyber gun sig 522 does.

Edit: I'll soon have some Modify Cylinder kits specifically for the sig 552

[Reckless]

S110 is 2 steps above the S90... there is a S100 in there too (I have one in my mp5)

[Jackarutu]

Thought I would include a comparison photo between the sig 552 and the Modify M4 cylinder to help the conversation on not using an M4 cylinder.




According to a spokes person @ Jag Precision (Modiy's US importer) in a bind you can get by using the M4 cylinder