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Old 03-10-2020, 06:34 PM   #1
RnB8819   RnB8819 is offline
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Good day, I'm having a bit of trouble with my unit for having inconsistent fps ranging from 460 fps down to 380 then up again to 470 fps... Im using Precision High Plus .25g bbs for this test... My internals are as follows:
JG Red Motor
TU Helical Gears
M140 Spring
Type 0 cylinder
SHS full metal teeth piston body
SHS aluminum piston head
SHS air seal nozzle
510mm x 6.05mm inner barrel
E&C stock metal hop chamber
JG Blue hop up bucking
Teflon mod

Test done:
Cylinder to air nozzle leak test- OK
Cylinder to inner barrel end test with piston on full rest postion- OK

But still I'm having 60-80 fps difference for every 2 or 3 shots intervals...

Tried to change spring to M120 but still the same...
Tried to install my 250mm inner barrel and hop chamber from my other unit and still the same...

Hope you can share your thought about this concern of mine...

Thank you...
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Old 03-10-2020, 07:00 PM   #2
1tonne   1tonne is online now
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Teflon Mod? What one are you meaning?
My bet is that your tappet plate is catching or rubbing on something when cycling. Often this can be hard to spot. They can rub on either the cylinder or the front of the gearbox.
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Old 03-10-2020, 10:01 PM   #3
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Have you tried with different BBs? Poor quality ammo would do this and I have experienced it first hand.
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Old 03-11-2020, 04:35 AM   #4
RnB8819   RnB8819 is offline
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Quote:
Originally Posted by Steveocee View Post
Have you tried with different BBs? Poor quality ammo would do this and I have experienced it first hand.
The bbs I'm using is the same quality as BLS...
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Old 03-11-2020, 04:38 AM   #5
RnB8819   RnB8819 is offline
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Originally Posted by 1tonne View Post
Teflon Mod? What one are you meaning?
My bet is that your tappet plate is catching or rubbing on something when cycling. Often this can be hard to spot. They can rub on either the cylinder or the front of the gearbox.
Teflon mod on hop up bucking and barrel for more sealing...

The tappet plate is moving freely during the rest position and I've tried to open the gearbox and there is no sign of abnormal rubbing on the tappet plate...
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Old 03-11-2020, 08:11 AM   #6
 
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Eh... could be your air nozzle is a little short, you could try swapping it out for a longer one. You could also trim your tappet spring by 2 coils to make it return faster. Also you could trim the tappet plate fang little to have the tappet plate start closing sooner.
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Old 03-11-2020, 08:45 AM   #7
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Quote:
Originally Posted by RnB8819 View Post
The bbs I'm using is the same quality as BLS...
May be true however that doesn't rule out the ones you have may/may not be a bad batch. For the cost of borrowing a few BB's from a friend, doesn't even need ot be same weight as the inconsistency would still show. It's worth a try.
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Old 03-12-2020, 12:49 PM   #8
bertha   bertha is offline
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Originally Posted by Steveocee View Post
May be true however that doesn't rule out the ones you have may/may not be a bad batch. For the cost of borrowing a few BB's from a friend, doesn't even need ot be same weight as the inconsistency would still show. It's worth a try.
Nice
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Old 03-12-2020, 01:38 PM   #9
1tonne   1tonne is online now
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I doubt it is the bb's.
Try taking the tefon off. Sometimes you can put too much on and it can cause all sorts of issues. Though I am pretty sure it is the Tappet plate catching. As Plaz said, you could try trimming the spring a little. Only one or two coils and no more as the excess stress can bend the tappet plate.
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Advanced L96 Sniper Upgrade Guide
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Choosing the right spring and making it work
https://www.airsoftsniperforum.com/32...tml#post127126
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