AEG mainsprings?

[emilianoksa]

I tried this on two other forums and got no reply. Is it too stupid a series of questions to warrant one?

Please bear in mind that I am a novice coming from spring piston airguns.

With airguns, when you fire the gun the spring is released. Now I have noticed that some G&G M4s have a mechanism that releases the spring before you store the gun. Why isn't the spring already released? And if it isn't (if it is held back under full compression after a shot) how do other guns without the G&G mechanism, allow you to decompress them?It is common knowledge that spring piston air rifles should never be dry fired. I assume this doesn't apply to aegs because people dry fire them all the time. Sometimes because they don't know the mag is empty. Can I safely dry fire an AEG?The CQB velocity limit for 0.20 bbs appears to be 320fps in the UK. If you buy a brand new gun for CQB that is rated to run higher than this, can you ask the retailer to get the power down to the normal airsoft site limit, by cropping the spring or replacing it?I'd be grateful if somebody could comment on any of these issues.

 

[Samurai]

Air rifles can't do full auto.

In full auto the system stops whenever you release the trigger, meaning it can stop even when the spring is fully compressed.

The single shot mechanism "releases the trigger" for you after each shot at a time when the spring is around its extended position (can differ based on the actual setup of the gun). That's why it is advisory to do a couple of single shots after the game ends.

Guns like the G&G you mentioned has a lever attached to the anti reversal latch, so you can disengage it and if the spring is compressed, it reverses the system to a relaxed position.

You can dry fire, but don't. The BB in the barrel creates some resistance for the piston, cushioning the impact. If you have a V2 gearbox (m4, mp5, g3, etc) a lot of dry firing can break it.

Downgrading depends on the store. Stores are not concerned if you play cqb with it or not, they are only concerned about being compliant with the law: sub 360 fps for full auto capable airsoft guns measured with 0.20g BBs.

 

[emilianoksa]

Thank you very much.

You have cleared up all the issues I asked about.

I am curious as to why so many people on videos I have seen dry fire their guns repeatedly. I assume they are not aware of the potential damage they may be doing to their guns.

 

[LightningCh]

Thank you very much.

You have cleared up all the issues I asked about.

I am curious as to why so many people on videos I have seen dry fire their guns repeatedly. I assume they are not aware of the potential damage they may be doing to their guns.

Click to shrink...

Or just for show, and it might be the only time they dry fire the gun otherwise.

From what I can gather it takes an awful lot to actually break the gun, and tbh, if it was like a serious and fast way of breaking guns, we wouldn't willingly dry fire 1-2 times before entering the safezone and still have the same AEG working for so long. 

I know I personally only ever dry fire it for chamber clearing in front of marshals, or when my mag has ran out, which is only a few trigger pulls at most. 

But we all know how humans in videos are and how stupid they can be sometimes lol, so guess it may also be down to them not knowing.

 

[Sitting Duck]

Thank you very much.

You have cleared up all the issues I asked about.

I am curious as to why so many people on videos I have seen dry fire their guns repeatedly. I assume they are not aware of the potential damage they may be doing to their guns.

Click to shrink...

We have to dry fire our toy guns to clear the chamber entering the safe zone

But a few single shots on semi won't harm an AEG....

Measures to help prevent or at least reduce risk of cracking...

Radius front of gearbox at cylinder...

&

Sorbothane or soft rubber/silicone washers to soften the initial impact

(topped off usually with a robust rubber/neoprene washer for durability)

Or more time consuming....

http://www.airsoftsniperforum.com/43-longrange-aegs/9062-guide-cylinder-head-damper-remold-bye-bye-sorbo.html

There are softer/silent piston heads

and only bolt snipers an air brake that at last few mm's plugs the hole to brake/brace for impact....

Not really an option fitting an air brake head on a snappy responsive AEG on auto

perhaps slight short brake for DMR but really air brake heads are for single bolt snipers tbh

But yup they do short air brake AEG piston heads for DMR but never used them myself

The idea is that the piston gets slowed the last say 5/10mm prior to impact

Not wise on an AEG cycling quickly - even on semi, the sector will mesh with piston

So a big brake is not wise, only a small tiny brake say on a DMR is a possible option...

http://www.booliganairsoft.com/2012/12/matrix-cnc-aluminum-devil-piston-head.html

Personally think just go with a softer so called silent head in a DMR perhaps

(just radius/sorbo also)

But really - what ever gives you decent compression/results

(too many people use a heavier spring to compensate for poor compression/results)

Power comes from spring and it is compressed inside piston

There is about 62mm space to compress say a 170mm spring

you can compress this spring slightly further by bearing spring guide and piston bearings/spacers

(though there are limits - avoiding guide/bearings/spacers bottoming out and spring compression limits)

Say you can compress a spring about 55mm (50mm is probably pushing it)

Or you can remove spacers to compress at say 62mm

Or you can remove teeth - Short Stroking on medium/shorter barrel guns (metal piston rack req) say 70mm

The same spring will produce different results resulting from larger/smaller energy on release in AEG's

(you don't always have to chop springs - heck can always fit a new correct spring also)

Irregular springs have tighter coils at one end and these are normally fitted tighter coils at back

if you reverse an irregular spring so tighter coils are at front of box/piston - you get aprox 10fps extra

So there is more than one way to drop/increase fps or skin a cat

As for dry firing....

Odd single shot dry firing is perfectly fine - we clear guns this way all the time

Dry firing on auto is done for testing purposes at times but usually not very often in comparison

Long term dry firing on high powered springs or high rps will promote cracking of the shells

(how long before it cracks is same as a piece of string - but it will increase the risks for sure)

Under "normal use" the bb acts as a tiny slither of a brake/resistance as it is propelled

(so it does not allow the full impact energy to slam into piston head/shell like dry firing)

It is more to do with the repeated impact or the resonance dry firing on auto for long periods

(and also repeated long term full auto firing over very long periods eg: rental guns cracking up)

Water boarding, high pitched sounds shattering glass etc.....

The damage usually takes place over a decent duration of time from continual/constant instance

$HIT HAPPENS, if a box cracks then you just replace it if it's a reg v2 v3 etc...

On more bespoke boxes, then YES you should take precautions to help avoid cracking

(Not always easy to source a L85, SR-25 v2.5 & others...)

But in general on v2 or v3's try ya best to help prevent/reduce cracking & wtf just use it how you like

chances are others bits will need replacing too, so what's a new shell/box in the end

stuff wears, $hit happens but don't go nutz dry firing on auto for 10 minutes (asking for it perhaps)

but don't crap yourself either to dry fire for say 5-10 secs now & then if you radius/sorbo etc....

there was a bloke dry firing an AK @ 400fps for 1 minute just to prove a point, SHS HT 11.1v 35c

(rest was stock after replacing steel rack piston, stock gears, cylinder head (sorbo), radius box....

just new motor & piston, I think it was valley arms in US but video has been deleted it seems)

Might have been a guy from Brill Armoury - I dunno it was a young Chinese US tech mofo

He basically wanted to shut up a HPA guy up that you can't do this to an AEG coz it will break

Well he ran the AK for a full minute at 395fps @ 30rps and still worked

(don't know if it started to crack up, but it proved a point to the HPA guy's argument)

Probably not wise to do this on regular basis but if done properly you can dry fire if needed

(but still like most things you take your own chances I guess)

So really it is all about a bit of preventative measures & a bit of common sense

(like most stuff in life I guess)

I wouldn't overthink stuff too much, you will end up like me (not a good idea)

just get out & use the damn toy gun, if/when it breaks (and it will most likely)

THEN worry about $hit happening

 

[emilianoksa]

Thanks a lot for that very comprehensive reply.

 

[Sitting Duck]

Thanks a lot for that very comprehensive reply.

Click to shrink...

That was a very brief response by my usual standards

EDIT - bit of a repost of an issue on spring compression but WTF....

Here is an example just how much you need to check stuff....
 
So found more robust metal piston, so lightened by moderate swiss

not putting back alloy spacer but a plastic 15mm 10mm thick spacer

much lighter at about 1.25gms than 6.5gms spacer or 4.5gms bearings

Usually I may not bother with any spacer if I'm going as light as possible

or use a 5mm spacer to replace/save weight of any piston head bearings

(normally I use 10mm spacer after ShortStroking but trying to keep fps)
So found more robust metal piston, so lightened by moderate swiss
not putting back alloy spacer but a plastic 15mm 10mm thick spacer
much lighter at about 1.25gms than 6.5gms spacer or 4.5gms bearings
 
Have the option of using a bearing spring guide which usually boosts fps
You lose a little fps from reducing the final stroke correcting AoE etc....
But I also replaced cylinder to a slightly further back port and compression
The compression now is awesome - really great instant almost
There's good compression and if you are lucky there is great compression
So hopefully with similar spacing and great compression etc...
Final fps should be or maybe a smidge higher perhaps
I could use a bearing bearing spring guide if I need to but in reality
I was just servicing a cheap basic gun with some old spares I have to hand
 
Now here are 6 x v2 spring guides
 

 
( This is not a display from a sex toy shop btw but 6 x aeg v2 spring guides )
 
Note 2 are std guides and 4 are bearing types
they all vary in height (more on that in a while)
But they also vary on the final amount they compress spring at back of box
 
Now the final spring compression will alter the fps slightly
3mm is the pitch of a piston's tooth and SS a tooth will reduce about 12fps aprox
So by varying the spring's final compression you can add/remove the final result
So if I need to alter the final fps I still can if it is just under/over site limit
 
Now note the height of all of these guides....
The black one second on left is std spring I was thinking of reusing
However I used a 10mm spacer AND a m3 threaded collar standoff
This protruded into the piston a good 2 or 3mm and luckily I checked stuff....
 

 
Picture is on its side btw
Note how the stock spring guide has just just started to touch the collar
So I will either file the top of black plastic spring guide a couple of mm
Or use say one of the shorter bearing guides in middle
If I had used the longer one on the far right it would have smashed into it
 
Because of 10mm spacer and more importantly the blue threaded collar
Normally I might use a large penny/repair washer & a m3 nylon locking nut
Or more often than not a piston head with m3 thread inside
This stock piston head is great seal, but has a cross-head m3 bolt inside
 
The complete piston now weighs about 22gms instead of 24.5gms
now it has a metal rack for durability and a couple of grams lighter
(could have got it down to 20gms but it's lighter so that will do)
 
However, I could have used the far right spring guide and run into trouble
Luckily I gave it the once over just to check stuff and saw WTF !!!!!!
 
Sorry for long winded post but a clear example of trying to improve stuff
(good ideas with all the best intentions)
But if not careful we can and very often make matters a lot worse
 
So as so many of us have learnt the hard way......
 
CHECK EVERYTHING !!!!!! (and I really mean everything)