[Plazmaburn]

The noise part is debatable depending on model of gun.

M14 hopup units are generally trash as they have tiny ass windows for the nub, which you can't use a regular size nub in anyway. I hate the gearbox in m14s as well just for all the crap that you have to take apart to open the damn things.

There are a few different designs of SVDs there is the king arms design, the classic army design, the real sword design, the a&k, and apparently LCT released their SVD (I'll post a link later). The real sword (and its clones) are the svds you ideally want if you are looking for an AEG. The gearbox is a bit proprietary in a number of ways, from the gear set to the trigger switch, and piston*. (Piston is a 19-tooth common for any gearbox that uses long cylinders. SR25, SVD, PSG-1, some brand I don't remember l85/l86. They are not all the same, I'll get into that later.) I know people freak out about the word "proprietary," it's just a cautionary flag. You need to be mindful of what mods and compatibilities you have and how brave you are with your modding skills.

Here is the ones I would recommend, if you are getting an SVD.

Echo1 Red Star AK CSR Airsoft AEG Rifle, Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Aluminum Receiver SVD-S Airsoft AEG High Power Sniper Rifle w/ Fixed Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard SVD-S Airsoft AEG Sniper Rifle with Folding Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard Full Metal SVD Dragunov Airsoft AEG Sniper Rifle w/ Synthetic Furniture (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore

LCT Airsoft SVD Series Airsoft AEG Sniper Rifle (Model: Black Polymer Furnitue), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore

What you need to know about the first 4 I linked.

These are the only replacement gears for it. Echo1 Gear Set for Red Star CSR / SVD Series Airsoft AEG Rifles, Accessories & Parts, AEG Internal Parts, Gears - Evike.com Airsoft Superstore

Piston Options- SHS Polygonal Polycarbonate Piston w/ Full Steel Tooth Rack for SR-25/L85 Airsoft AEG Rifles, Accessories & Parts, AEG Internal Parts, Pistons, Polycarbonate Pistons - Evike.com Airsoft Superstore
UFC Airsoft - SR-25 Type - Full Tooth Steel and Polycarbonate Hybrid Airsoft AEG Piston, Accessories & Parts, AEG Internal Parts, Pistons, Polycarbonate Pistons - Evike.com Airsoft Superstore
Retro Arms Fulltooth Piston with 17.5 steel teeth for SR25 / L85 / MOD25 / BR10 (Gen. 2) - Pistons - AEG Rifles - Tuning & Internals (begadi.com)
Piston incl.Piston Head for Begadi Sport MOD25 / BR10 (19Z) - Pistons - AEG Rifles - Tuning & Internals
SHS Piston with 19 steel teeth for L85 / SR25 -yellow- - Pistons - AEG Rifles - Tuning & Internals (begadi.com)

All of them use 7mm bushing/bearings. I used these in my main, you will need 2 packs. Begadi 7mm ceramic hybrid ball bearing, flat - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals
If your into bushings, Begadi PRO -7mm- CNC Stahllaufbuchsen mit Laserbeschriftung (6 Stück) - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals
FPS Softair 7mm Stahllaufbuchsen Set (8 Stück) für Begadi SVD / SVU Sport Serie (BPSVD) - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals

You could upgrade the gearbox to 8mm. SVD (bullgear.net)

(on an unrelated note. I want to get this for my AK. Hop-Up AK (bullgear.net))

Here is the limited info I have gleamed about the LCT.

Electronic Trigger, Quick change spring system, CNC aluminum cylinder head and piston. Uses only LCT mags.

 

[Whamhammer]

Piston travel is parabolic, but the pressure spike at the hop rubber occurs almost immediately after the piston achieves compression, wherever that happens to be. Heavier pistons accelerate more slowly,

Heavier piston = slower piston acceleration = less pressure behind the air at the hop rubber spike.

Piston travel is linear, not parabolic.

No, heavier piston = slower INITIAL piston acceleration, and less INITIAL pressure. The longer cylinder provides extra distance for the force exerted upon it to continue to accelerate, past the distance that 15 tooth cylinder allows the spring to convert potential energy to kinetic energy. Remember that the spring is significantly longer than the total Piston travel allows, so a 19 tooth cylinder is still converting potential energy to kinetic for 4 teeths worth or so more distance because force is still being exerted upon it without having a significant force opposing it, where the 15 tooth piston had a more abrupt stop due to significant force opposing it. Refer to all three Newtons laws for this one.

 

[Whamhammer]

The noise part is debatable depending on model of gun.

M14 hopup units are generally trash as they have tiny ass windows for the nub, which you can't use a regular size nub in anyway. I hate the gearbox in m14s as well just for all the crap that you have to take apart to open the damn things.

There are a few different designs of SVDs there is the king arms design, the classic army design, the real sword design, the a&k, and apparently LCT released their SVD (I'll post a link later). The real sword (and its clones) are the svds you ideally want if you are looking for an AEG. The gearbox is a bit proprietary in a number of ways, from the gear set to the trigger switch, and piston*. (Piston is a 19-tooth common for any gearbox that uses long cylinders. SR25, SVD, PSG-1, some brand I don't remember l85/l86. They are not all the same, I'll get into that later.) I know people freak out about the word "proprietary," it's just a cautionary flag. You need to be mindful of what mods and compatibilities you have and how brave you are with your modding skills.

Here is the ones I would recommend, if you are getting an SVD.

Echo1 Red Star AK CSR Airsoft AEG Rifle, Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Aluminum Receiver SVD-S Airsoft AEG High Power Sniper Rifle w/ Fixed Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard SVD-S Airsoft AEG Sniper Rifle with Folding Stock (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore
CYMA Standard Full Metal SVD Dragunov Airsoft AEG Sniper Rifle w/ Synthetic Furniture (Package: Gun Only), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore

LCT Airsoft SVD Series Airsoft AEG Sniper Rifle (Model: Black Polymer Furnitue), Airsoft Guns, Airsoft Electric Rifles - Evike.com Airsoft Superstore

What you need to know about the first 4 I linked.

These are the only replacement gears for it. Echo1 Gear Set for Red Star CSR / SVD Series Airsoft AEG Rifles, Accessories & Parts, AEG Internal Parts, Gears - Evike.com Airsoft Superstore

Piston Options- SHS Polygonal Polycarbonate Piston w/ Full Steel Tooth Rack for SR-25/L85 Airsoft AEG Rifles, Accessories & Parts, AEG Internal Parts, Pistons, Polycarbonate Pistons - Evike.com Airsoft Superstore
UFC Airsoft - SR-25 Type - Full Tooth Steel and Polycarbonate Hybrid Airsoft AEG Piston, Accessories & Parts, AEG Internal Parts, Pistons, Polycarbonate Pistons - Evike.com Airsoft Superstore
Retro Arms Fulltooth Piston with 17.5 steel teeth for SR25 / L85 / MOD25 / BR10 (Gen. 2) - Pistons - AEG Rifles - Tuning & Internals (begadi.com)
Piston incl.Piston Head for Begadi Sport MOD25 / BR10 (19Z) - Pistons - AEG Rifles - Tuning & Internals
SHS Piston with 19 steel teeth for L85 / SR25 -yellow- - Pistons - AEG Rifles - Tuning & Internals (begadi.com)

All of them use 7mm bushing/bearings. I used these in my main, you will need 2 packs. Begadi 7mm ceramic hybrid ball bearing, flat - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals
If your into bushings, Begadi PRO -7mm- CNC Stahllaufbuchsen mit Laserbeschriftung (6 Stück) - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals
FPS Softair 7mm Stahllaufbuchsen Set (8 Stück) für Begadi SVD / SVU Sport Serie (BPSVD) - Steel Bushings & Ball Bearings - AEG Rifles - Tuning & Internals

You could upgrade the gearbox to 8mm. SVD (bullgear.net)

(on an unrelated note. I want to get this for my AK. Hop-Up AK (bullgear.net))

Here is the limited info I have gleamed about the LCT.

Electronic Trigger, Quick change spring system, CNC aluminum cylinder head and piston. Uses only LCT mags.

The L85/L86 19 tooth system in question, is the G&G replica (to the very least). I don’t remember if any other manufacturer uses a 19 or 15 tooth setup; pretty sure the ICS replica is a 15 tooth, but I may be mistaken.

 

[Leo Greer]

Piston travel is linear, not parabolic.

No, heavier piston = slower INITIAL piston acceleration, and less INITIAL pressure. The longer cylinder provides extra distance for the force exerted upon it to continue to accelerate, past the distance that 15 tooth cylinder allows the spring to convert potential energy to kinetic energy. Remember that the spring is significantly longer than the total Piston travel allows, so a 19 tooth cylinder is still converting potential energy to kinetic for 4 teeths worth or so more distance because force is still being exerted upon it without having a significant force opposing it, where the 15 tooth piston had a more abrupt stop due to significant force opposing it. Refer to all three Newtons laws for this one.

I meant to say acceleration was parabolic. I have seen a piston before.

I didn’t disagree with you. I was speaking about air pressure at the hop rubber, not at the end of the piston’s travel. Initial acceleration is what I was referring to:

Heavier pistons accelerate more slowly,

Heavier piston = slower piston acceleration = less pressure behind the air at the hop rubber spike.

 

[Faitfull]

The L85/L86 19 tooth system in question, is the G&G replica (to the very least). I don’t remember if any other manufacturer uses a 19 or 15 tooth setup; pretty sure the ICS replica is a 15 tooth, but I may be mistaken.

I belive that g&g and army l85 is 19 tooths. However there is some issues with both. Something about piston stripping if run with a good battery.
The rest use standard piston.

 

[Faitfull]

Some people i talked with, said i dont really need a svd at 2.8j. That a v3 or v6 gearbox should more than needed. Your thoughts?

 

[Leo Greer]

They’re correct—you can get there. It’ll just be easier with a longer cylinder. Nothing wrong with either path; one can be more difficult and cumbersome to play with, and the other might cost you some durability,

 

[Whamhammer]

I meant to say acceleration was parabolic. I have seen a piston before.

I didn’t disagree with you. I was speaking about air pressure at the hop rubber, not at the end of the piston’s travel. Initial acceleration is what I was referring to:

I was hoping you were meaning acceleration, but I have heard some really out there thought before

The one thing to keep in mind, as far as a typical V2 setup and a 2.5 SR25/M110/AR10, is that the nozzle of a V2.5 is 24.00mm long, almost 3mm longer than the typical M4/M16’s nozzle.The extra length allows for longer travel to the hopup bucking, so the parabolic increase in piston speed, longer nozzle, and heavy BB has more of an opportunity to have the needed increase of pressure to match and possible exceed the pressure spike of a V2, with a 21.00-21.25mm nozzle.

Have I pressure tested the two, and compared? No, but if there wasn’t a notable performance benefit increase, as seen by the manufacturers, I am pretty sure that they would have gone with a V2, with a bore up setup, and a longer hopup system that let the into barrel sit a little further back into the hopup, to have the same length of travel for it, as the M16/M4’s do.

Does that make sense?

 

[Faitfull]

Regarding upgrade path on the svd.
It uses halv teeth. Very important.

Also begadi have 2 different gearsets for it. Normal cyma and speciel treated cnc gearset.

 

[Whamhammer]

I just notices something, Faitful, the OP, just brought up V3’s and V6’s, arent all HK G3/T3/etc replicates based off of the V2 family, not V3 or V6? Or am I jumping the shark, and the V3 & V6’s were just mentioned because they are 15 tooth piston gearboxes?

Asking for a friend….😁

 

[Whamhammer]

Some people i talked with, said i dont really need a svd at 2.8j. That a v3 or v6 gearbox should more than needed. Your thoughts?

I agree with LEO, a 15 tooth gearbox can be used to reach 2.8J, the issue is that the 15 tooth setups a noticeable percentage less air volume than a 19 tooth setup, so the 15 tooth system has to work that much harder, have that much more spring rate, have that much of a stronger motor, that much more stress on itself.

At that power level, having every mechanical aspect being precisely crafted, assembled, and QC is that much more, critical because the wear and tear will be significantly greater, and there is that much less room for error, before the stress results in a chewed piston, lunched spur gear, ruined bushings/bearings, etc.

 

[Leo Greer]

I was hoping you were meaning acceleration, but I have heard some really out there thought before

The one thing to keep in mind, as far as a typical V2 setup and a 2.5 SR25/M110/AR10, is that the nozzle of a V2.5 is 24.00mm long, almost 3mm longer than the typical M4/M16’s nozzle.The extra length allows for longer travel to the hopup bucking, so the parabolic increase in piston speed, longer nozzle, and heavy BB has more of an opportunity to have the needed increase of pressure to match and possible exceed the pressure spike of a V2, with a 21.00-21.25mm nozzle.

Have I pressure tested the two, and compared? No, but if there wasn’t a notable performance benefit increase, as seen by the manufacturers, I am pretty sure that they would have gone with a V2, with a bore up setup, and a longer hopup system that let the into barrel sit a little further back into the hopup, to have the same length of travel for it, as the M16/M4’s do.

Does that make sense?

Trust me… I’ve heard some crazy stuff. I swear half the guys at my field genuinely think FPS is controlled by how big your battery is.

I would be very interested to do a study on the two that compares performance between setups in an objective as possible sense. My gut tells me V2.5 for better performance.

Good catch the extra nozzle length. How relevant is 3mm? I don’t know that answer. Probably somewhat.

Whenever I get the time I’ll do some performance and accuracy testing on a ported cylinder vs. a full cylinder (V2) and that might be able to give me a better idea of whether or not the differences between the two (and between V2 and larger cylinders) is actually large enough to be a real thing, and not just a tiny difference.

Some manufacturers do use an alternate system: G&G… and I can’t remember who else use an extended cylinder head and nozzle that’s reputed to be quite bad…

 

[Plazmaburn]

I have an ICS it is for sure a 15.

Regarding upgrade path on the svd.
It uses halv teeth. Very important.

Also begadi have 2 different gearsets for it. Normal cyma and speciel treated cnc gearset.

It does not use half teeth, and begadi gears, didnt know about them. Nothing really special about them though, still roughly the same torque, just has a galvanic nickel plating on them. "CNC machined" does not mean much from carbon steel gears.

So far the stock gears will handle a m210 and have not stripped out yet.

 

[Whamhammer]

Trust me… I’ve heard some crazy stuff. I swear half the guys at my field genuinely think FPS is controlled by how big your battery is.

I would be very interested to do a study on the two that compares performance between setups in an objective as possible sense. My gut tells me V2.5 for better performance.

Good catch the extra nozzle length. How relevant is 3mm? I don’t know that answer. Probably somewhat.

Whenever I get the time I’ll do some performance and accuracy testing on a ported cylinder vs. a full cylinder (V2) and that might be able to give me a better idea of whether or not the differences between the two (and between V2 and larger cylinders) is actually large enough to be a real thing, and not just a tiny difference.

Some manufacturers do use an alternate system: G&G… and I can’t remember who else use an extended cylinder head and nozzle that’s reputed to be quite bad…

The “Extended Cylinder” V2 SR25s are sold by Golden Eagle/JG/Echo1/Matrix. I think that heard that Avengers brand does but never heard of anyone actually owning one of those.

The only manufacturers actively making V2.5 “AR10” platforms are A&K, Classic Army, and CYMA; G&P stopped making their V2.5 AR10s a few years ago. As a side note, Classic Army has made V2.5 SCAR-H’s as well.

 

[Leo Greer]

The “Extended Cylinder” V2 SR25s are sold by Golden Eagle/JG/Echo1/Matrix. I think that heard that Avengers brand does but never heard of anyone actually owning one of those.

The only manufacturers actively making V2.5 “AR10” platforms are A&K, Classic Army, and CYMA; G&P stopped making their V2.5 AR10s a few years ago. As a side note, Classic Army has made V2.5 SCAR-H’s as well.

Never bother to learn the technical difference between the V2.5 and the V2L… to me they’re both just “that long sucker over there”.

 

[Leo Greer]

Here y’all go: if you listen closely you can hear the separate cylinder and barrel noises.

 

[Whamhammer]

Here y’all go: if you listen closely you can hear the separate cylinder and barrel noises.

I’ll be honest, I can’t hear an

Here y’all go: if you listen closely you can hear the separate cylinder and barrel noises.

I got nothing…. I also have some hearing damage from ‘splosions and boomie things, and working 20 years near air tools, perhaps the sound you want me to hear is in a deaf spot for me.

 

[Leo Greer]

I’ll be honest, I can’t hear an

I got nothing…. I also have some hearing damage from ‘splosions and boomie things, and working 20 years near air tools, perhaps the sound you want me to hear is in a deaf spot for me.

It’s hard to catch—I’m lucky my ears are still young. Give me a few years to catch up.

 

[Whamhammer]

Never bother to learn the technical difference between the V2.5 and the V2L… to me they’re both just “that long sucker over there”.

Easiest way to look at the technical difference between the two, the V2.5 makes complete sense for a DMR platform, and was likely designed by a person that enjoys airsoft, and their job; the V2L makes no sense, and was designed by someone that not only hated airsoft and their job, they were an exiled KelTec engineer, that instead of getting a model train full of cocaine to make it through hardcore design sessions, was given acid, with an embalming fluid chaser.

I am allowed to say this with a degree of certainty because I have actually owned both gearbox setups, and I could still smell the embalming fluid on a certain gearbox.

 

[Whamhammer]

It’s hard to catch—I’m lucky my ears are still young. Give me a few years to catch up.

You could call it age, you could call it that you lacked the propensity to make career choices that were likely to do permanent harm to yourself; either choice is likely correct 😁