[philbegas]

Hey guys. This is my first official Information/upgrade thread but I wanted to make a really comprehensive one because not very many people had them out there. So I apologize if it needs some work, but I will do the best I can and feel free to ask as many questions as you need to, and I will answer them as truthfully as I can.

1. Choices while picking a SVD
2. Stock internals
3. Upgrading it

1.

Several years ago I bought the King Arms SVD AEG from the CPO department at Airsoftmegastore. It cost me $150. I am from a Russian/Ukrainian background (born in moscow, raised in russian household in america). And as a result I have always had an affinity for russian guns. I also am also a fan of longer-range shooting. So naturally I had a choice, either the SVD, or the VSS. At the time I bought the SVD, there was no VSS available that I was interested in, and I liked how the SVD looks anyways.

Now when buying a SVD you can go with several different options. First off there's gas, spring, and electric. I know nothing about the spring SVDs so I won't waste your time. With the gas ones however I know a little bit. You can choose between the g&p, king arms, we-tech, or aim. Here's what I know about them:
Aim: Lots of problems due to plastic internals breaking.
We-tech: Some fps consistency problems, can be solved with o-rings.
g&p: Collectible item but POS for actual field play
King Arms: I think this one is pretty new, it doesn't seem like anybody has bought it or at least reviewed it yet so if you have, let me know!
I've emailed ra-tech directly, and they said their NPAS system should fit the We-tech SVD which is good news! Because all GBB SVDs shoot too hot for most fields for Sem-auto. Somebody told me there's a NPAS that fits the Aim but I have not heard anything about which one it is.

Now, onto the ones I know something about; electric.
You really have these choices for AEG SVDs: RS, KA, CYMA(echo1), CA, A&K.

Cyma & A&K are clones of the RS with their 4 gear T3 RS gearbox set up. Which means that you can replace your internals with RS internals (generally considered better). Or the small selection of upgrade parts.

Then there's the CA/KA Svds. Now, I don't want to talk too much about the Classic Army. But I've heard that it's the same general gearbox set up as King Arms, in the sense that it has a M14/v7-style box (not interchangeable) that uses Sr-25 gears. I will go more into details about the King Arms SVD in the next part of this thread obviously.

RS: Now, this is the cream of the crop. More than double the price of any of the other ones. And to be honest, I wasn't feeling it. I read lots of threads about people upgrading them because they aren't quite good enough stock, but I preferred to start with a 150$ gun and upgrade, than with a 600$ gun. Some people swear by it, but I had my reasons. I also prefer polymer furniture to real wood. I might buy some real wood furniture at some point to go along with it though.

If you have any questions feel free to ask me and I will answer to the best of my abilities. Please do not attack me for feeling the way that I feel about the real sword svd (I am expecting it). I am entitled to my opinion, and in the following posts over the next couple weeks I will detail why I ended up making my choice once I show you the internals and the potential.

 

[philbegas]

So guys I'm going to start going through the KA SVD AEG internals starting with the gearbox. This is how it looks minus the spring and the motor spring (in a box somewhere).


The gun uses Sr25 gears, and an elongated (possibly v2.5 cylinder). It uses a short type motor with relatively weak magnets. The motor cage is mounted horizontally, similarly to a m14/v7 gearbox. The cylinder head is also a v7 BUT the wings of the cylinder head are slightly too long so I'm having to dremel the wings down a little bit (well to be honest my brother is doing it hehe) but the nozzle is in the right place.
Here is a comparison with a normal cylinder head



Here is the cylinder compared to a regular cylinder



The piston itself is made of some kind of polycarb material, it seems pretty strong, and the AoE is not bad stock. Barely any wear on the piston teeth. But instead of putting a proper SR25 piston in it, they just put a weird extended piston head on it. The compression is pretty bad stock though. There's a lot of work to be done, which I will detail at another time.



Also the spring guide is strange. The gun takes AEG springs, but the spring guide has some kind of extended lip. I've placed it next to a V3 spring guide. The length from the lip to the tip is the same, so if I use PSG1 springs it should be good!



Now moving onto the weird part. Here is the hop up:





It is a proprietary rotary hop up. It's pretty consistent, but the hop-up arm needs some shimming. The hop up stock is pretty decent, I get some pretty decent reach. There is NO replacement, so if my hop up breaks, I guess I'll have dome DIY mods to do, or to buy a new gun. The hop up is the same as the spring KA SVD hop up as far as I know, and those are cheaper to buy, so either way I can buy a gun and sell the parts for spares.

Hmmm other things. Comes with 7mm bearing bushings. and a brass barrel. Anything I'm forgetting feel free to mention it!

 

[Cpt Skeptic]

Have the same gun, and the spring guide is poop. It broke after a few spring changes. I'm using a regular V3 spring guide and a 150 spring. Works great so far and getting 200 ft body shots on .28's Just under 390fps. Had to do some work on the hop up unit, it's cheap plastic not nylon so be careful with any work. Modify flat hop really works well once you get it right.

 

[philbegas]

Oh nice
I want 450 fps for semi so I'm going to get a 200p% fsg1 spring

Edit:

That weird spring guide means you need longer springs, and PSG1 springs are longer.

 

[philbegas]

And this is a list of the stuff that's going to be going into/onto the gun:
SHS reinforced steel standard torque SR25 gears
SHS Shims
Super Shooter V3 CNC spring guide
Extreme-fire SW-Lynx mosfet (just ordered it)
ZCI 22tpa high torque neo motor (short)
Turnigy Nano-tech 2000mah 11.1v 15c-25c Lipo
ZCI v7 Cylinder head (with the wings dremeled down)
Matrix CNC Sr25/L85 piston w/integrated piston head
Lonex Ak nozzle
Madbull Version 2 650mm 6.03 tightbore
RTX Flat hop
I also have a v7 sorbo 3/16 but it's too long so I'm going to get a thinner one.
I got a cheap-o SVD bipod
UFC illuminated 4x26 psop scope
DIY:
Going to IR-hop a new barrel. Found out that the madbull have an inner coating which means after heavy use the coating starts to chip off and cause inconsistencies.
I'm going to run a volume test (with windex) to see what kind of length barrel I should actually get. I imagine 650 is too long so I'll probably end up downgrading to a 590. Possibly widening to a 6.05. I'm going to see what kind of fps/grouping/range I get with the existing barrel before deciding.
Teflon mod
My piston already has holes in it so it doesn't need to be swiss-cheesed.
I'm going to lock my gun into semi by removing the selector switch.
Going to rewire with better wire as well.

 

[absorbedsponge]

I'm curious as to how the version 7 cylinder head is going to work! Please update if the v7 cylinder head has the correct location for the air seal nozzle to seal well in the hop up unit. Along with other things such as feeding, or modifications needing to be done to the tappet plate.

I'm also curious if a v6 cylinder head would work. If you dremmel out the area by the nozzel to make it look like a v7 it may be a better fit. The reason I say this is because I think a v6 cylinder head is not a centered cylinder head, and the offset may be closer to the king arms cylinder head. If someone has some info on this please post.

I have been trying to bore up this gun (yes bore up an extended gearbox). Without a bore up cylinder head to pair with the bore up cylinder it is very hard to make a good airseal between the cylinder head and cylinder. But preliminary results show the bore up to allow for much better joule creep (this has been true for the sr25). Also I wouldn't use a 650mm barrel just because you want to use a heavy bb for accuracy. A 650mm barrel may be adequate for a .20g bb and provide the best fps results, however for maximum joule creep a 600mm-500mm barrel will probably provide better results for joule creep.

Also as side notes for teching this gun.
1.
Orga magnus psg1 bore up cylinder does not work (well?). It is about 1mm shorter then the original cylinder head. This causes an issue with either the piston being pulled out of the cylinder or the cylinder not fitting onto the cylinder head fully, allowing an airseal leak. I have been working on making this seal but sadly I have not yet accomplished this feat fully and I have leaks with heavier weight bbs. The other issue is that with a bore up the cylinder inner diameter is now much larger then the original and such the cylinder, cylinder head air seal leak is larger. I had made a custom o-ring but it isnt' working perfectly, so the next try was to glue it together with the o-ring. I will update results on this when I have time to work on this gun.

2.
With a tappet plate modification you can sand it thinner by the air seal nozzel to allow the nozzel to move farther back. If you do this you will need to increase the sector gear pull back notch so that the tappet plate is moved back by about .2-.4mm's-ish. This may not seem like a big change but it can allow for a much better airseal inside the hop up unit by using a slightly longer airseal nozzle without feeding issues because it is pulled back farther.

3.
Be careful of the spring guide used in the gun. Make sure it is extremely stable when inside the gearbox. To test this put the spring guide inside without a spring and see if it can wobble. If it can it could cause a catastrophic jam.

Phil, great post, and great images. I have been looking for these images everywhere on the interwebs. Many of these internals do not have images online. I will update with any information I find out.

Another thing if someone also knows. If anyone happens to own a KA svd and a CA svd a cross compatibility list would be awesome. This is a longshot but would be invaluable information.

Please post what is known, or suggestions as to what needs to be tested so compatibility parts can be found.

 

[philbegas]

Okay so I'm going to try to respond one point at a time:

-The nozzle for the v7 is in the correct place (the cylinder head just needs to be upside down from how it is in a normal v7 GB.

-I'm probably going to end up downgrading to a 590mm. Maybe even a 540ish. Just depends on my volume test and fps/grouping results once I put everything else in there.

1. I'm *pretty* sure you need an extended sr25 cylinder. It uses sr25 gears and a sr25 piston so I don't see why not. I've seen a few bore-up sets for sr25 cylinders. I might try getting one. We'll see. I'm not sure it's worth the effort I've read bore-ups are hit or miss
Product Details

2. Is a good idea but I don't know anything about tappet plates so I'm not sure what kind of replacement to get if I fuck it up.

Thx for the kind words

These are the compatabilities that are 100%
Short motor
sr25 gears
sr25 piston
ak nozzle
v3 spring guide IF you use PSG1 springs (which are longer)
7mm bushings
Things that could be helpful:
v6 cylinder head testing

 

[POP414]

I just purchased one of these and I am very happy to find out theres info like this on our forum!

I do have a couple quick questions/points:

Couldn't one use a V3 spring guide and just put a spacer at the front of the piston (inside the spring hole, not on the piston head)? Just a thought for further research.

And in some of the research I read I could swear I saw someone say that a V7 tappet plate works in this gun, but I am not 100% sure by any means.

 

[002215]

I am about to upgrade my King Arms SVD AEG with some new parts, and what I was told by evike was to put in a thrust bearing piston head instead of a new spring guide. I chose to buy the Bravo Aluminum Piston Head w/ Thrust Bearings. I will inform you on how it holds up with the stock spring guide.

Also, here is a list of all that I will be putting into my gun:
Matrix Silent CNC Aluminum Ver.7 Cylinder Head for M14
Matrix L85 / SR25 Type CNC Aluminum Steel Strip Piston & Piston Head Set
King Arms H.Q.A. Airsoft AEG Hopup Bucking - 60 Degree / Normal Type
CNC POM Nozzle for AK47 AK74 Series Airsoft AEG by Guarder / AIM Top
Matrix Ultra Precision Gun Smith Airsoft AEG Gearbox Shim Set (40 pcs)
Systema M120 Irregular-Pitch Airsoft AEG Power-Up Spring (380~420 FPS)

 

[philbegas]

Sorry it's been so long sinve I've been online. I ended up botching the wiring job so I sent it off to ASGI. The v7 cylinder head turned out to be a lost cause, even with dremeling it just didn't sit right. Not sure what was going on.

When I email airsoft gi next I'll ask them if they think it's just a v7 tappet plate but you might be right Guarder M14 Tappet Plate [Version 7] - Airsoft Atlanta

As for the v3 spring guide you can't use a spacer because it's a quick-change spring gearbox so you need to make sure the spring guide fits in the notches and doesn't have the potential to pop out of the rear of the GB

 

[dran671]

Sorry it's been so long sinve I've been online. I ended up botching the wiring job so I sent it off to ASGI. The v7 cylinder head turned out to be a lost cause, even with dremeling it just didn't sit right. Not sure what was going on.

When I email airsoft gi next I'll ask them if they think it's just a v7 tappet plate but you might be right Guarder M14 Tappet Plate [Version 7] - Airsoft Atlanta

As for the v3 spring guide you can't use a spacer because it's a quick-change spring gearbox so you need to make sure the spring guide fits in the notches and doesn't have the potential to pop out of the rear of the GB

I've only worked on a TM M14 once, but I do believe that the compression set is shorter than the SVD. I'm assuming, since the sector gear will engage at roughly the same point, that the SVD tappet would actually be longer than a V7. Perhaps taking a RS SVD tappet and cutting would work better as it is the only other of the 19t piston fam that has a tappet spring that pushes rather than pulls.

What I used was an Ares spring guide for the QD box.
[Army Force] Aluminum Spring Guide for QD Transform Gearbox

It fits right in with no modification, though I needed to replace the screw-on endcap as this spring guide had a wider threading. I just used a screw and washer. This endcap is necessary as it acts as a stabilizer for the spring guide.

Also, I'm checking fitment with an Ares V7 CH. Waiting for arrival any day now.
http://shop.ehobbyasia.com/ares-cylinder-head-for-m14-ebr-m14-sopmod-aeg.html#.Va1KP_mqqko

I noticed that the wings are already shorter than average V7. I remember reading somewhere that some Ares gun was shorter than TM style. I figure if it's too short, I'll close gap with rubber pad. If it's too long, I'll grind it, then close gap with rubber pad. Haha.

 

[Zerosliver]

Just wanted to clear up something about the RS SVD. Obviously the main reason you'd buy it is for the awesome realistic externals. But it seems people are getting the impression that upgrades are necessary for it to perform better.

Let me just say that most people who upgrade the barrel to a Prometheus or PDI, like me, just want to get maximum performance and are willing to spend money on that. The stock barrel and bucking are fine and definetely already perform greatly. Nothing on the gun needs replacement at all.

 

[dran671]

Following up on the fitment of the Ares CH, it fits in perfectly. I had an ALUM V7 CH from ASG, I think it was, and the bore was slightly too large to fit the stock cylinder, although not being a bore-up. It also had wings that were far too long. The Ares V7 CH has double O-rings and creates a perfect air seal with Lonex POM PH, stock cylinder, and SHS short AK ASN. The side notches fit over the pegs fine and the box closes. The CH tube extends as far as the stock and is at the exact position as stock when inverted. The wings have a bit of clearance from the front of the gearbox, so I cut up an extra sorbo I had and glued it to the front as a buffer for the heck of it. It's steel and has sorbo on front and back. I think it should have great shock dampening. It's only running M140 with SHS poly 19t and Lonex POM PH w/bearing. I want to take every precaution for a shell with no drop in replacement.

What I mentioned earlier about the different lengths is the differences between TM and CA/G&G M14's. But you probably know that. It makes sense that it would accept the CA type V7 CH due to the box being originally CA design. I also found that the cut-off lever is very similar to the CA/G&G M14 cut-off lever. It looks like it should be a drop in replacement, although it wouldn't function properly with the selector, therefore the replacement would render it permanently semi, which is exactly what you should be doing, anyway. I plan to test fitment later. I don't know if trigger placement is the same, so it might be too short.

I also found that SR25 gears have a longer cut-off engagement tooth than L85 gears, and will jam with the cut-off lever unless one or the other is shaved. I don't have the most steady hands, so I chose to buy new gears instead of risking speeding up wear to a part with no OEM replacement (besides buying the A&K SVD box).

Lastly, I noticed that the CA and A&K boxes have a long, sloping support for the corner, which would help against gearbox crack. The KA is significantly less dramatic, although still there, with no definitive corner. Would you reckon this makes cylinder radius unnecessary? I'll post pics later to better illustrate what I'm getting at.

Honestly, I'm wondering if this KA SVD was worth the trouble when I could've bought a CYMA with a better aftermarket. I've found the A&K box, but it looks like it would disable the charging handle (and still doesn't sell parts only). Also, the CYMA has a readily available real wood version. I'm having trouble finding aftermarket wood accessories with the hollow handguard for AEG.

 

[Lolzamarofl]

I have the A&K AEG SVD that I acquired from a teammate back in Feburary, and the gearbox looks the same as the one you have in the picture, but it has a QC spring guide instead of a regular one, and mine came with a normal piston with no elongation.
My A&K SVD was great when stock, it could reach 200ft with .25's at 360 fps all stock.
However, the itnernals were different than what you have. The gears have been replaced with v2/v3 18:1 SHS gears (which do fit and work well) and the piston with a regular SHS 14 tooth piston topped with a Modify piston head. However, I will say that the stock nub in the A&K does get worn out really quickly and ends up not applying as much hop-up over time.
Your thread was a good read, just thought some extra information may be wanted/needed!

 

[philbegas]

Personally
I DO think cylinder radius is unnecessary for the KA gb.
But here's what happened while the techs have my gun:
They said the piston was engaging my spur gear. But honestly I sent off my gun to ASGI because they're known for doing a pre-upgraded KA SVD AEG, and that's effectively what I wanted (except with better parts I chose). So the matrix L85/SR25 piston I chose has rails that are either too small or too thin. They're currently working on resolving the issue. I'm honestly wishing I had just bought a CYMA SVD because replacement parts are readily available. Or just a Real Sword because i wouldn't need any parts ;_;

 

[philbegas]

And fortunately I'm not planning on taking my FPS above 450ish so once it is finally resolved it should have a long life

 

[philbegas]

SO
Long time no post. Felt like I needed to update y'all.
My piston didn't match the gears. It kept catching the spur gear. I had to switch to a g&g co alloy piston for l85/sr25
Also I had to go with a different spring guide but now it's working like a dream. 425-430 fops with .2
Going to take it out as soon as it stops being 100F

So the Ares v7 CH fits in the King Arms gearbox?

 

[1IV]

Am I correct in reading that you used the SHS140? I ask because I just picked up one of these and I'm going to go ahead and bring it up above 430 trying to get right up to the limit. I'm going to try a 150 and I'll let you know if the FPS is. Zurn when making an aftermarket hop for yet? I'm tempted just to go ahead and HPA this.

That's a good question : Has anybody ever HPA one of these? Wolverine makes a drop in for a version three- looks like it'll go in this fine...

 

[1IV]

Ok I found the 150 reference and the 200% reference - how did the 200% perform with that upgraded piston?

 

[shadowghost]

You can buy the hop up from King Arms for $18.