New to Upgrade Help

[Josefgerbils]

Hi all. 

Be prepared for a lot of stupid questions! Whilst I am not new to airsoft,  I have just been one to pull the trigger and see it shoot. Never understood the witchcraft of internal......doings. that's kinda changed recently . I purchased a lovely aeg that I soon had the hankering to go DMR with. I felt a little more power was in order as the gun was very accurate at its stock 310fps  but was unsuited to my particular playing style. I opted to do a simple spring change and see what happened.  I opted for a 120 spring  and was happy with an accurate just under 400fps . My problem is that's very battery specific.  I get just below 400fps on 8.4 and 9.6  but dropping down to 7

4v the power drops off to 348fps  . That's on a fully charged battery. Does battery have that much effect on power?  I was always led to believe that it didn't. Or am I putting my gun under too much strain with a 120 spring ? Please forgive the stupid question,  but I'd rather have a gun running stock than a wreck.

Cheers 

Bob

[EDcase]

Battery shouldn't affect power as long as it can pull the piston back.

[Josefgerbils]

So you think it could be a case of the spring being too powerful for the battery @ 7.4 ? If so am I wrecking my gun ? 

Or was the stock gun intended to run on a bigger battery?  So therefore it takes that to move the piston effectively? 

[Josefgerbils]

Or ....is the 7.4 just knackered? That theory works , because if it runs fine on both other voltages,  then why not that ?

[EDcase]

Yeah, could be the 7.4 is dying tho as said, if it can actually cycle and fire then it should have same fps as the others.

Have you got a good LiPo balance charger?

 

Obviously having a stronger spring will put more strain on all the components.

[Adolf Hamster]

If its pulled the spring back all the way then it should be the same fps (assuming there's no leaking) as at that point it's all the spring.

 

You can get a full auto fps drop from pme where the piston gets caught by the sector again before it's finished its travel but that shouldnt be happening here.

[Zarrin]

33 minutes ago, Adolf Hamster said:

If its pulled the spring back all the way then it should be the same fps (assuming there's no leaking) as at that point it's all the spring.

 

You can get a full auto fps drop from pme where the piston gets caught by the sector again before it's finished its travel but that shouldnt be happening here.

 

Yeah, if anything a more sluggish cycling rate is gonna help you avoid that kind of pre-engagement.

 

As people have said above, the batt really should not have any effect on fps, once that last tooth disengages from the piston it's all kinetic and pneumatic energy; voltage isn't a factor.

 

have you tried hot swapping back and forth between your 7.4 and one of the 8.4/9.6 while taking fps readings all the way through? 

[Josefgerbils]

Thanks for all the replies guys. I have tried swapping and taking readings. And a 120 spring is not too extreme an upgrade for an aeg. Just baffled by this. Will do a fresh set of chronograph readings later and pop them up

Cheers 

Bob 

[ak2m4]

Hi Bob, ideally for a DMR you'd swop out the motor for a high torque and run with a 11.1v battery.  It will work with a 7.4v of course.  Sounds to me like you've made a slight mistake with the Chrono readings, let us all know what results you get with some more readings.  Always take about 10 readings and take the average

[Josefgerbils]

Just in the process of charging all 3 varieties of battery.  A fully controlled science type thing is being prepared.  All shots will be taken with .20 bb over 10 shots per battery.  Have to charge them first in the interests of base lab conditions.  I will get to the bottom of this (with your help) of course 

[Josefgerbils]

Ok after a full night of testing I have found the elephant in the room. Tried 2 7.2 v and 1 8.4v and 1 9.6v . For some bizarre reason all batteries apart from the suspect 7.2 gave readings just under 400 fps , the problem battery gave readings of 350 fps ish. Not quite sure how its happening but I think the problem almost certainly lies with that battery.