How to Downgrade but keep good FPS?

Inari

Hey folks,

First and foremost, yes I am a n00blet to all this stuff. Now that it's out of the way, I'll get right down to it:

As a result of an affinity for movies, and loving guns/army from quite a young age, when I found out about Airsoft being legal, I knew it was something I had to do. I got a beautiful M9, and quickly found that I wanted an AEG...but money was tight, so I had to buy overseas. I got a good deal, and bought a Jing Gong M4.

Now, I want to downgrade it, because the website I bought it from tested the batch at an average of 335 fps, and to be honest...the gun certainly feels powerful. The problem is, I want to retain as high an FPS as possible, whilst complying with the law, as I wish to be able to use it as a sniper rifle.

How do I go about doing this? Since I have no experience working with AEG's, should I bite the bullet and pay for the service, without knowing how much the gun will be reduced? Or do I try downgrade it myself, without the facility of testing its FPS to see if it was succesful, and possibly risk damage to the gun.

I really appreciate you guys reading this, and hope you can help. Thanks,

~Inari,

Firekitten

Take it to an airsoft shop near you to get it downgraded... whether you want to or not, the gun MUST fire at 328fps to be legal.. if its over that, and the gardai catch you.. it can spell prison time. Consiering you;re new, its best to go to a professional for this... how much will they downgrade it? enough to make it legal

TheDoc

A quick google search will show you probably a step by step take down on how to go about opening your gearbox to the point where you can replace the spring.

However if your not confident just drop it into a shop and they will fix you up, its a small fee to pay for the heartbreak you could endure..

(Doc remembers back to trying to replace a stripped piston in his g36c..that ended up in a cup)

Inari

Firekitten wrote: »

Take it to an airsoft shop near you to get it downgraded... whether you want to or not, the gun MUST fire at 328fps to be legal.. if its over that, and the gardai catch you.. it can spell prison time. Consiering you;re new, its best to go to a professional for this... how much will they downgrade it? enough to make it legal

That's a fair point, and don't get me wrong, I do agree with you. Like, at the moment the gun is literally just a decoration and never leaves my house. I've already been in contact with a retailer about the downgrade, but this post was more so seeking advice from yourselves. I was just wondering if there's a way to control how much you reduce it by cause, as I said, I'd like to have the option of using it long range (i.e. sniping).

@Doc: Thanks for the advice on the physical changing of the spring. Would changing the spring to a lower grade cause damage to the gun? Sorry for all the (most likely) stupid questions...just eager to learn.

Firekitten

It wont cause damage no... and the spring 'strength' controls fps... you can get it to literally what you want... as long as its legal... and i might point out that even owning it hot is somewhat dodgy legally... its best to get it downgraded asap...

TheDoc

Inari wrote: »

That's a fair point, and don't get me wrong, I do agree with you. Like, at the moment the gun is literally just a decoration and never leaves my house. I've already been in contact with a retailer about the downgrade, but this post was more so seeking advice from yourselves. I was just wondering if there's a way to control how much you reduce it by cause, as I said, I'd like to have the option of using it long range (i.e. sniping).

@Doc: Thanks for the advice on the physical changing of the spring. Would changing the spring to a lower grade cause damage to the gun? Sorry for all the (most likely) stupid questions...just eager to learn.

lowering the spring strength wont cause any problems, if anything it eases stress of the rifles internals. Remember where these rifles are made they are heavily distributed to chinese and american retailers, they are built from factory at 380+ fps.

You can off course get your fps in an around a consistent limit, but its really much hit n miss trial and error, by snipping springs down till you get it to consistently under 1 joule.

I just advice anyone wanting to do it them selves aim for 300-310fsp.

FPS is over rated, the difference between 300fps and 360 fps is not noticable, so its bull**** saying theres an advantage or it "hurts" more, there isnt.

But aim for 300 so when you go to some sites that sometimes give obscure chrono readings, youll be sound either way.

Inari

Thanks for that folks. I really appreciate it. My dad said he's gonna drop me to the retailer next week, so I'm happy:)

My main concerns were the spring damaging my rifle, or the fps falling too far for what I want it for. Hopefully i'll see you all out in the field in the near future:)

Masada

Any retailer worth their salt will be able to give you a fairly reliable 310-320 average and know what to install before even opening it.

If you feel confident with the screwdrivers you could always give it a bash yourself but make sure to do your research before you do it. theres a few tricks you can pick up from online videos before taking the plunge.

horgan_p

do yourself a favour , and as the guy / girl has the aeg apart , get a hop rubber stuck in. If you're feeling flush get a tightbore barrel as well.

Both are excellant vaue for money upgrades.

Shiva

Firekitten wrote: »

..... even owning it hot is somewhat dodgy legally... its best to get it downgraded asap...

Heh heh......I know thats not what you actually meant, but just in case anyone reads too much into that - its not "somewhat dodgy" - its illegal.

Firekitten

wasnt too sure if it was 'using it' or having it' that made it illegal... Thanks Tony...

BornToKill

Firekitten wrote: »

wasnt too sure if it was 'using it' or having it' that made it illegal

That would be both. Over one joule makes it a firearm and section 2 of the Firearms Act says

'every person who after the commencement of this Act has in his possession, uses, or carries any firearm without holding a firearm certificate therefor or otherwise than as authorised by such certificate, or purchases, uses, has in his possession, or carries any ammunition without holding a firearm certificate therefor or in quantities in excess of those authorised by such certificate, or fails to comply with any condition subject to which a firearm certificate was granted to him, shall be guilty of an offence'.

The penalties are fairly serious - a fine of up to €20,000 or jail for up to seven years, or both. 'But it's just a hot Jing Gong'; in the eyes of the law it is just the same as an unlicensed Glock or Beretta. Watch those fps is my advice anyway.

Firekitten

First thing I did after realising my TAR-21 was hot was rip the spring right out and downgrade... I'd rather have less range than Jail time! Plus its part of the game... we all run the same fps, its fair, there's no advantages one can have and another cannot...

Inari

Aye, having the same fps is a great thing...means that whoever has the most money isn't strictly at an advantage. But even if it wasn't the law, the sites would still impose an FPS limit, so it'd remain the same:)

Once again, thanks for all the advice...it is really appreciated.

TheDoc

horgan_p wrote: »

do yourself a favour , and as the guy / girl has the aeg apart , get a hop rubber stuck in. If you're feeling flush get a tightbore barrel as well.

Both are excellant vaue for money upgrades.

There should be a sticky on this forum explaining to people how increased fps does **** all, its A) illegal end off and it makes no difference

I know paul and myself can speak from experience, going toe to toe with 400+fps rifle in sweden.

I think he has a similar setup to mine, with a tightbore barell and good hop rubber in EVERYTHING!.

I cannot believe I played 8 months of airsoft and didnt realise the huge difference these cheap and simply installed parts make.

Its like driving a car in second gear for a year, then someone saying " you know you can go into 3rd,4th and even a fifth"

Inari

You have raised more questions for me, if you wouldn't mind answering I'd be much obliged:

- What exactly does the tight bore barrel do? I assume because of the name, that it's a much tighter fit, which would create more pressure behind the BB making it more efficient and accurate as the force is directly behind, and not slightly under, over to the side. That is literally just a guess based on the name.

- Roughly how much would it cost to get a tightbore barrel installed? Would it be worth putting into a JG M4? Can I salvage it after if I move up the makes?

- Noob time; it says it already has hop-up...is it just not worth much, or virtually non existent? Just wondering if it's worth the money.

- How much would the hop up be?


Once again, sorry for all the questions...but thank you for taking the time to read them:)

TheDoc

A tightbore barell is basically, a tigher barell. The diameter is tighter. This means less air escapes around the BB when fired, so you get more of a punch. This in turn will give you more accuracy and range, because the BB isnt slightly moving side to side in your wider barells. This will however raise your fps, but only a little.

The hop up rubbers that come standard on most AEG's are too hard. Remember I said these guns are made firing 400+fps stock, so the hop up rubber is harder to combat these higher limits.

At 1 joule, this rubber is so hard, it requires alot of hop up to work efficently. However, should you get a better rubber, designed for 1j, you can get a much more efficent hop up. Because the rubber will be softer, it will grib the BB better, and in turn you wont need to use as much hop up to get the same effect as the hard rubber. This in turn, means you wont experience as much of an fps drop when turning your hop on, and your hop is much more efficent getting better spin, giving more range.

Thats my take on how it works anyway.

Inari

Any idea on what it'd cost (rough guestimate) to both buy and install?

TheDoc

I think it would work out around 30-40 euro for both to buy online. Then install yourself.

Think its bout 40 to get them installed by a retailer.

dirdeen

the f'in site i bought my new gun off never downgraded it, think she's firing at 385FPS what price are we lookin' at to get it downgraded over here and do the likes of eirsoft do it?

Inari

Yeah, Eirsoft do stuff like that. I PM'd the user 'Shiva' about it for a quote

dirdeen

cheers dude, ill get onto that

Leftyflip

Where did you get the gun from? Take it back to them and ask them to downgrade it as it is firing over the limit.

tmason

i've bought mine and it was firing at 0.5-.6J ~260fps, it turned out that cylinder and nozzle were drilled, got new (full) cylinder and nozzel, new cylinder head (old one was driller through too) and new piston head, installed new tighter barrel (6.03), PDI 120% (M90) spring and new hop-up chamber, i sealed everething and now I've got 328fps sporadicaly jumping to 330 and dropping to 325fps...so good luck

TNTQ

Both cylinder and nozzle were drilled? That is very bad. So acctually value of your AEG was lower by the price of new parts and labor.

Leftyflip

tmason wrote: »

i've bought mine and it was firing at 0.5-.6J ~260fps, it turned out that cylinder and nozzle were drilled, got new (full) cylinder and nozzel, new cylinder head (old one was driller through too) and new piston head, installed new tighter barrel (6.03), PDI 120% (M90) spring and new hop-up chamber, i sealed everething and now I've got 328fps sporadicaly jumping to 330 and dropping to 325fps...so good luck

What gun was it? Most cylinders have holes in them. What did the retailer advertise the FPS at? To be honest if I bought an AEG that fired at 260 fps and it was advertised to fire at 300fps, I would have brought it straight back to them. But atleast your gun fires quite nicely now.

tmason

it's cybergun - some cyma clone, i know some cylinders' versions have holes, but these were drilled manually and unprofessionaly, aparently sometimes when guns are sent over to ireland from overseas they drill holes instead of replacing springs and properly downgrading guns, anyway I got some parts from retailer discount free of charge so no problem

TNTQ

tmason wrote: »

it's cybergun - some cyma clone, i know some cylinders' versions have holes, but these were drilled manually and unprofessionaly, aparently sometimes when guns are sent over to ireland from overseas they drill holes instead of replacing springs and properly downgrading guns, anyway I got some parts from retailer discount free of charge so no problem

Probably many people will disagree with me, but drilling anything in the AEG equals with destroying the replica.

When drilling is done, some of the metal fillings are getting into the gearbox (which is no, no). Then cylinder have a sharp edged whole in the way of piston (another no, no).

Drilled nozzle have increased chance of breaking when it hits something hard.

Frank the Manc

TNTQ wrote: »

Probably many people will disagree with me, but drilling anything in the AEG equals with destroying the replica.

When drilling is done, some of the metal fillings are getting into the gearbox (which is no, no). Then cylinder have a sharp edged whole in the way of piston (another no, no).

Drilled nozzle have increased chance of breaking when it hits something hard.

have to agree with you Andros, anything other than changing the spring is for the stetson and spurs brigade.

whatever about drilling an air nozzel which can be replaced and at worst the swarf is only plasic so the most it will do is damage your hop rubber, drilling a cylinder leaves metal swarf inside your gearbox, may damage the o-ring on the piston head and where a real John Wayne has done the drilling, may even drill straight through your piston or piston head.

and it can be un-downgraded in about 30 seconds with tape or chem metal or if its a type zero cylinder, simply reversing the cylinder.

TNTQ

My biggest conecern is acctually the un-downgrading. And after shooting 30,000 round you will probably notice drop in fps because of probably damaged o-ring.

tmason

of course drilling is not a good idea, but now everything is perfect and instead of fps "jumpig" all over the place they keep at constant level.

TNTQ

tmason wrote: »

of course drilling is not a good idea, but now everything is perfect and instead of fps "jumpig" all over the place they keep at constant level.

FPS will be jumping only if something is done incorrectly. Another problem with drilled guns is wear and tear of internals. You have Gearbox with spring being able to generate 400-450fps, shooting at 320fps. In other words, lifespan of your equipment is shorter than it would be with weaker spring. Not to mention increased Rate Of Fire with spring 90 instead of 120.

Masada

TNTQ wrote: »

My biggest conecern is acctually the un-downgrading. And after shooting 30,000 round you will probably notice drop in fps because of probably damaged o-ring.

You;ll do a lot more than 30k rounds to an o-ring though, some people could do that much in the first few weeks of using the gun. I have a rifle thats up over 100k and the o-ring is grand, you just need to clean them every now and then.,

Frank the Manc

TNTQ wrote: »

FPS will be jumping only if something is done incorrectly. Another problem with drilled guns is wear and tear of internals. You have Gearbox with spring being able to generate 400-450fps, shooting at 320fps. In other words, lifespan of your equipment is shorter than it would be with weaker spring. Not to mention increased Rate Of Fire with spring 90 instead of 120.

exactly, unnecessary wear and tear on a GB.

and from what iv seen a drilled cylinder or nozzel will give flucuating and spoardic results from, it might be a reasonably consistant 310-320ish and then drop to 190 and then up to 350.

a good prommy spring and a decently sealed hop & barrel assembly is your only man.

Forget about chasing the 328, a good hop unit and rubber shooting at 280 will outrange a stock 380fps clone all day, it may take a second longer to get there but i doubt you will be shooting too many Morpheus' out there.

range,accuracy and consistancy are king.


vetc: i think he was refering to compression loss due to a damage o-ring as a result of having the cylinder/piston/piston head drilled.

Masada

Frank the Manc wrote: »

vetc: i think he was refering to compression loss due to a damage o-ring as a result of having the cylinder/piston/piston head drilled.

Ahh i see what ya mean, ive seen 2 Beta spetz that were drilled like that, seems baffling as to why they did it.