I heard that Guarder bore up air nozzle is shorter for about 1 mm. Could this be reason of my low fps.
Is Deep Fire Enlarged Air Nozzle (for M4) better?
I made a can shoot test to determine my fps, and it didint penetrate bottom, not even both sides (just one) of the can. ( 0,2g BB) So it is probably less then 350 fsp...

Precision barrel:
Madbull 6.03 $35 or
Deep Fire 6.04 $35 or
Prometheus 6.03 $48
??? (your choice)

I can't comment on Deepfire parts. I don't use them, because many other AEG builders I talk to say they are garbage, and I don't like to waste money, so I don't put garbage in my guns.

"Enlarged" nozzle sounds like some sort of Engrish description of a Bore Up nozzle.

And please, get access to a real chronograph. The can test is crap; it's very inaccurate because the thickness of metal used in soda cans varies from place to place.

if a prommy barrel is only $13 more, there is no reason not to get one.

Thank you guys for all your useful advices...

battery trouble
 

Hello again,
there is one thing I am struggling with. My Sanyo 9,6V 3300mAh battery.
After I full charge it and leave it be over night, it discharge itself, so the motor wont spin even though it tries (you can hear click sound). It seems to be quite strange. After I plug it in the charger for few minutes, than it is able to spin the motor. My charger is TLP Fuzzy Logic Expro
Also when I am charging the empty battery charger stop itself for about 30 minutes indicating that battery is charged, after I plug it again it continues with charging for another 30-60 minutes. I have to do that approx 4 times until the charging period shortens to less than 1 minute…
I don’t know where the problem is , battery and charger is 1 year old and very rarely used.

Update:
I was reading through the forum and found one topic where has been said to charge new batery with 0,1C, If I understand correctly it means to charge new battery with 3,1V (in case of 3300mAh). I never did this. I always charge with 1,2 V.
Maybe I could try to deep cycle it with 3,1 V. Hopefuly it will wake up...

Your problem is certainly battery if it's 1 year old and not properly cared for it is likely dead or close to it especially if is rarely used. NICD packs should be cycled once a month or two. and NiMH packs topped off.

What is the chemistry of the pack?

Charging at .1c-0.5c is the best way to take care of your pack in the long run.

Its NiMh

Do not cycle Charge NiMH it will kill your battery, You should be just topping off the battery every couple months or before you play.

And normal charging voltage 0,1-0,5C??
And first (after purchase) charging voltage 0,1C?? (formating)

I tryed to charge my current byttery with 3V, but I could set on my charger only 2,3 V max. So i discharge it and then it was possible to set charging voltage 3,0V (and more).
But during charging, voltage slowly dropped from 3,0 to 0,8V.
Mybe it was some protection function from charger to keep the temperature of baterry down, or I dont know. Battery was warm, but not hot.

I'll buy a new Elite4000SC battery anyway...

thats what I was doing for whole time....

After partial upgrade
 

So after almost final upgrade my gun status is:
chrono: 300-350 fps (0,2g bbs)

PDI 170% seems to be very incosistent and weak spring
I would expect higher (aprox. 400) fps with this spring...

* inner barrel Prometheus 6,03 - 363 mm length
* standard ratio systema gears
* systema hop-up
* GP M120 motor
* new elite 4000 mAh NiMh battery (quite high ROF)

Ater installing new barrel bbs are shooting quite inaccurate. Aprox 20-30m and then its going up and down. I tried to remove any oil from the rubber (washing in hot water) but no difference.
I am going to be despered, still no satisfied wiht my very expensive gun....

You used a PDI AEG spring.. That's your problem.

Go get a prometheus M120 if you want 420ish FPS.

Is this your model?
http://www.gp-web.com/en/productspop.php?pid=1535

PDI210% is approximately around M130 spring rate. Provided if your smithing skills are good enough and you’re running both ends with bearing, you’ll get that figure.

I’ve not handled an original PDI210%, accidentally bought a fake one :’( , but generally PDI springs are longer than the Guarder’s.

The spec says it’s 8mm Bearing GB. Just change it to a 8mm bushing. Bearings are a no go for high springrate nor a super high ROF setup.

Get a good brand 11.1v 15c or 20c lipo. Then get the JG M-93 Red Motor. Pair it with stock ratio gearset (reinforced, but stock ratio). Should hit the ROF you’re aiming. Get your AOE, shave the 2nd and 3rd tooth flat to avoid pre-cranking/stripped piston.

Are you sure your AEG uses short stem motors? V2 gearboxes usually uses long type motors (unless if it’s VFC/Dboy’s PDW, which uses mid length motors). Those programmable MOSFET systems can in a way, control the ROF by playing with motor speeds. Unfortunately, FPS is fixed with your hardware.

Questions:
Is the “PowerUpgrade all titanium teeth piston” full metal or was it polycarb with metal tooth? Full metal (heavy) pistons aren’t good for high ROF setups.

have your system properly cronoed for both FPS and RPS. That will get you actual figures instead of guestimation. Parts is just half of the equation. Skills plays an important role at the final results too.

I've seen 3XXfps with a M140 spring too. I've also seen 480+ fps with a stock AnK spring. Best thing is, the 3XXfps with M140 spring sounds much more powerful than the 480fps stock spring. LOL

What is the most suitable piston for my gun? My piston with all metal tooth is lowly getting KO. So I am considering to buy a new one.
I am using spring Prometheus MS135, modify smooth gear set torque and Systema silent cylinder and piston head.
Can I use sorbo pad together with systema silent piston head? (replacing the rubber)
THX