SR25 is not shooting properly, different sound of shooting

[maxiyou]

Hello! Actually I have problem which I just can't solve for 2 weeks... After tuning of my new A&K SR25 (changing inner parts) my rifle is often shooting improperly (BB's are flying wherever they want) with different sound from these when BB's are flying straight. First of all, I've got nozzle from Pro-Tech (bad polish ASG brand) and some guy which work in service said that nozzle is fitted bad in cylinder and spring from magazines is pushing too much so nozzle can't deal enough power to kick BB's from barrel - he adviced me to spray on nozzle with grease and after doing that my SR25 shot well for a short time. I decided to buy new highly recommended nozzle for SR25 - Deep Fire AUG nozzle... but problem is still happening... I've got 2 mid-caps from A&K and 1 hi-cap from also A&K (this one worked great before tuning). Also I used different brands of BB's.
Changed parts:
- silent piston and cylinder set from Systema,
- SHS high speed gears for SR25,
- Deep Fire AUG nozzle,
- SP140 Guarder,
- King's Arms chamber,
- Systema black bucking.
If my english is a bit bad, I'm sorry cuz I'm still learning

 

[Lozart]

Can you try putting the original nozzle back in to see if that cures it?

You've changed a lot in one go so it will be difficult to say exactly what the problem is. You need to try and eliminate one thing at a time.

 

[Sitting Duck]

- SHS high speed gears for SR25,

Click to shrink...

This might be an area to investigate.....

if that is the SHS set with a sector using a bearing

this " might " not retract the tappet back quite as much as the std 19 tooth sector and due to bearing you can't fit a delay or much other mod stuff

plus a new tappet plate is tricky to locate - though gunfire have a few in stock

http://gunfire.pl/product-eng-1152200327-Tappet-plate-for-the-V2-L-SR25L-replica.html

though they say the yellow CA tappet plate is better - dunno but either are hard to locate at times if you need a new one

I'd see if you can use the stock sector and maybe with a delayer

this may retract the tappet/nozzle further back than the SHS bearing one

well - this is perhaps what needs to be checked I think

I've not started my sr25 yet but have noted a few posts I have read and think I read somebody having issues after using shs set too

hope some of this helps

 

[Sitting Duck]

- Deep Fire AUG nozzle,

Click to shrink...

AHHHHHHHH

Lozart could have the nail on the head - again.....

didn't notice that bit at first glance - my bad

The nozzle lengths do vary especially as G&G uses a normal short v2 box with a long nozzle

The general length "seems" to be around 24mm

your aug might be 24.75mm so could be too long:

Id' suggest maybe one of these two or both:

http://gunfire.pl/product-eng-1152205816-AR10-Nozzle.html

and/or

http://gunfire.pl/product-eng-1152200134-Nozzle-for-the-CA25-type-replicas.html

the interesting thing is this:

http://gunfire.pl/product-eng-1152209177-Nozzle-for-AUG-Replicas.html

Nozzle for AUG Replicas

A tightened nozzle dedicated for SR25 replicas. Made from durable polymer.

http://gunfire.pl/product-eng-1152205815-AUG-Nozzle.html

AUG Nozzle



A tightened 24,75mm nozzle dedicated for AUG type replicas

So you may have a nozzle too long for the gun and hence feed issues

get the shs or the other one

poxy sr25's - a lot of info varies and difficult to get a confirmed deffo answer plus the few bespoke bits are not easy to get when you need them - so maybe grab a few spares whilst you can

I'll know more when I crack mine open soon and hopefully can confirm for sure what is what rather than stab guesses at stuff

 

[maxiyou]

So I changed WHOLE inner parts to stock, all like before in the same place, and problem is still happening... I tryed 3 different nozzles (Deep Fire AUG, CA25 Pro Tech and my old stock nozzle). Reassembling HU chamber did nothing too. Two things I don't have from old set-up are old gears (they are broken) and old spring. I think that nozzle is moving in the right cycle, because this problem is happening once for maybe 4,5,6 shots? Don't know kick me if I'm not right.

 

[maxiyou]

But look what I said - when I used teflon grease spray on nozzle then SR25 shot for 500~ BB's in right way and after this I walked home. Coincidence or some clue?

 

[Lozart]

But look what I said - when I used teflon grease spray on nozzle then SR25 shot for 500~ BB's in right way and after this I walked home. Coincidence or some clue?

Click to shrink...

I don't think the walk home has a lot to do with it.....

I have to say I'm startin to think SD had it right with the gearset. If you've changed everything back to stock EXCEPT the gears then by deduction I would say the issue would have to be the gears (unless you're just putting it back together badly every time).

When you say you greased the nozzle - I presume you meant inside the nozzle? So it slides back and forth on the cylinder head better? Or do you mean on the outside so it slides into the hop unit better?

 

[Sitting Duck]

ok

3:00 in - check bb's push past the bucking lips with push test

now misfeed is mainly but NOT limited to:

mags

bucking too tight - will have trouble chambering or feeding a bb

nozzle not clearing to chamber - wear or tappet not retracting enough

alignment

2nd & 3rd are common problems

is barrel too tight or crap bb's - egg shape bb's don't feed too great

spraying nozzle is just asking for trouble

does nozzle fit inside hop unit or does it snag

some hops can be slightly too tight and the nozzle doesn't slip inside smoothly - or of box/hop are misaligned the nozzle scrapes and doesn't enter hop fully which could stop it chambering into hop

there are a number of things - but changing loads of stuff in one go has not helped coz just means you have to closely check & examine more parts in greater detail

 

[maxiyou]

I don't think the walk home has a lot to do with it.....

I have to say I'm startin to think SD had it right with the gearset. If you've changed everything back to stock EXCEPT the gears then by deduction I would say the issue would have to be the gears (unless you're just putting it back together badly every time).

When you say you greased the nozzle - I presume you meant inside the nozzle? So it slides back and forth on the cylinder head better? Or do you mean on the outside so it slides into the hop unit better?

Click to shrink...

I sprayed outside the nozzle to improve BB feeding. So about testing chamber - BB's are just like in the video staying at bucking and with little pressure they are slightly getting out from the barrel. Nozzle is just perfectly fitted inside chamber, just in the middle. I've still got old piston gear from stock so I can try it tomorrow and see what will this do. I think chamber and barrel are good because they are in the same condition as they were when gearbox was stock and everything worked well. 1 more thing about the gears... When they arrived and I changed them, piston gear wasn't able to turn of electricity so on semi I've got auto and after improving that piece of metal which is responsible for cutting signal everything was fine. Point is that these gears surly can be defective or something. Like I said tomorrow I will try old piston gear.

 

[Lozart]

I sprayed outside the nozzle to improve BB feeding. So about testing chamber - BB's are just like in the video staying at bucking and with little pressure they are slightly getting out from the barrel. Nozzle is just perfectly fitted inside chamber, just in the middle. I've still got old piston gear from stock so I can try it tomorrow and see what will this do. I think chamber and barrel are good because they are in the same condition as they were when gearbox was stock and everything worked well. 1 more thing about the gears... When they arrived and I changed them, piston gear wasn't able to turn of electricity so on semi I've got auto and after improving that piece of metal which is responsible for cutting signal everything was fine. Point is that these gears surly can be defective or something. Like I said tomorrow I will try old piston gear.

Click to shrink...

If you've lubed the outside of the nozzle then you'll have contaminated the hop rubber. So you'll need a new one of those.

 

[maxiyou]

If you've lubed the outside of the nozzle then you'll have contaminated the hop rubber. So you'll need a new one of those.

Click to shrink...

If you've lubed the outside of the nozzle then you'll have contaminated the hop rubber. So you'll need a new one of those.

Click to shrink...

Please, that was a little amout and generally that didn't affected shooting in any way. No change needed seriously. Once upon a time when I was starting with ASG I greased a whole magazine and after this I ruined my barrel and bucking After cleaning a bucking I still use it in my M14 with same effectivness so that doesn't matter.

 

[maxiyou]

I tested it while ago with old gears and problem the same. I have no idea. Whole problem looks like pistone & cylinder setup can't get enough compression sometimes or something. Any ideas? Maybe I can do that without sending it to service...

 

[maxiyou]

I changed bucking and problem is still happening

 

[Sitting Duck]

Without having the thing in front of me......

If you say the bb can pass through the bucking lips ok

then I'm tending to think the nozzle is not retracting enough

you will have to check this yourself.....

place the nozzle+tappet plate in the top/right half of gearbox

then place the sector gear in there

this is a better & more accurate way to see the amount of retraction you have.....

rotate sector gear so that is pulls the tappet plate back to its max point

look at the gap in front of tappet - 8mm would be nice

anyway place hop unit up against the front of box and ensure the nozzle is completely clear of feed tube & can't see the nozzle etc....

push tappet/nozzle forward and you should feel resistance at its furthest point forward - aprox 1mm to 1.5mm resistance

That is the basic checks on tappet travel - back far enough to chamber & forward enough to seal

this test is best done in the right/top side of gearbox as trying to check this in the left/lower half has too much play/wobble on gears/bushings to see exactly imho

Also perform this check without cylinder first and then with cylinder

the tappet could be clearing loads on its own but bottoming out on the cylinder head stopping nozzle retracting 101% all the way

this will create rapid wearing of tappet fin or extreme cases can break/damage tappet plate itself

So check this without & then with cylinder - mark stuff with pencil if you wish blah blah blah

The other thing to check is the tappet plate spring has enough tension - you can lose a coil

well bend a coil over to increase tension or new spring

you don't want insane tension as too much tension is likely to slightly increase wear on tappet fin sooner

enough tension to push bb forward quickly with sufficient force - only on higher speed guns will this need to be much greater

can't say exactly in Newtons or crap but you should have a decent amount of spring on that nozzle at front

As I say I haven't got it in front of me but you need to check stuff how it seems to operate

your nozzle might be too long

the sector bearing/cam may not retract the tappet/nozzle enough

bucking lips jam

tappet spring too light

mags not feeding with enough tension

to be honest "usually" guns tend to feed ok on semi - if gun doesn't feed reliably on semi you really have bad feed issues

on auto as speed increases and it has little time to chamber - misfeeds start happening more often

The clever bit is to try and diagnose the exact issues first and then once the main issue is narrowed down

then you can consider alternatives & possible suggestions/solutions

swapping bits around back n forth and all over again is just stabbing in the dark if I'm honest

you need to examine and monitor closely what is taking place to cause these issues

I can only offer suggestions and methods to try to help narrow it down a little as to the main cause

if you can examine the components in operation a little closely then we might be able to help rectify the real issue

try and carry out a few close checks yourself to see if this is ok or that is working correctly first