a quick spring related question

[rich1988]

Hiya, I bought an A &K SR 25 a few weeks back, obviously it shot too hot out of the box (430) so It needed downgrading to be used at my local site, I cut two coils off the spring which initally reduced the FPS down to 360 which was perfect, however after a days use it dropped to 320 then the next time I went out it dropped to 150 !

I replaced the spring with one I aquired from a friend which was shooting at 370 in his ak47, I drop it into my rifle and it only shoots at about 300 (one side of a can) my question is why is this ? is it because the internals of my gearbox are so much heavier and therefore will I need a 120 to get me to sort of 350 ish area?

sorry for the fragmented post but any ideas/advice would be apreciated!!

[Garf3r]

Re: a quick spring related question

mm this is a weird one. it could be because you clipped the first spring, thur maybe damaging your internals, but i wouldn't think that the case.

Does the AEG when fired sound like its in any way struggling? I.e funny noises, sound like its having trouble turning the gears, piston movement etc..
What battery you using? It charged enough?
Checked the hop up?
Checked the barrel is aligned correctly? (no sure if its a one peice or what)

[rich1988]

Re: a quick spring related question

hiya cheers for the response, the internals all seem perfectly happy, no stripped cogs and with the spring removed it all turns very happily, It doesnt sound as if its struggling and with the new (weaker) spring it has an impressive ROF and all the internals sound and seem to be running smoothly.

The battery is fully charged and the hop up turned off. the power originally just seemed to drop from full power to barely nothing without any noise or drama I think its just that that spring is knackered but what I cant understand is that a spring that fires at 360/70 in one gun fires at abotu 300 in another.

In saying that the other gearbox is almost an inch shorter than mine and seems to have lighter gears, could it simply be that do you reckon?

(battery is fully charged)

[bushmonkey]

Re: a quick spring related question

what I cant understand is that a spring that fires at 360/70 in one gun fires at abotu 300 in another.

it could be (like you thought) to do with a different mechbox...nothing to worry about, just get anew (slightly more powerful) spring

[Barny Hamon]

Re: a quick spring related question

The SR-25 gearbox is slightly bigger than standard ones, so any spring you put in would give you less power than a standard aeg. Unless you use spacers but im not sure if that would work. You could get a higher powered spring but it would be under performing right away. Im not sure what the correct course of action would be here though.

[rich1988]

Re: a quick spring related question

I did think about spacers and nearly tried them but the pistons comes all the way back and nearly touches the end of the spring guide so it unfourtunatly wouldnt work, I suppose I just need to get myself a more powerful spring, the box is obviosuly designed to take it (firing at 430 standard), suppose I drop a systema m130 in there (normally 430 fps) i wonder if it would drop the 60/70 fps to around 350/60? reckon its worth a try?

[Barny Hamon]

Re: a quick spring related question

I suppose so, though you cant be certain what fps it will come out with.

Anyway its worth a try.

[rich1988]

Re: a quick spring related question

Well I suppose its just going to be a case of trial and error? unless I can find someone else who has one, thinking back as well someone else at our skirmish site bought one and put a M100 in it which normally fires at 350 (I had one firing at 360 in my G3 to start with) but it was firing at 280, so it does seem like it fires around 60 fps under what you would expect so I may give a 130 a go.

If its too hot Ill jsut have to buy a 120 or wear it in I suppose, thanks for the advice guys

[The Keeper of Secrets]

Re: a quick spring related question

The A&K airseals aren't the greatest things out there. It could be that your mat's AK had a much better airseal, and so was able to harness more of the spring's power. That and the fact that SR25 gearboxes are longer. That's pretty much why it's giving the resutls seen.

Mu advice would be to do what you're planning, experiment with springs until you find one that works

[bushmonkey]

Re: a quick spring related question

if you buy a spring, and it turns out to be too hot, i am sure that someone on here would buy it....

[rich1988]

Re: a quick spring related question

I need to buy a new chrono as well now (yay) one of my friends thought it would be a great idea to try and chrono a shotgun through a chrombo and in a word it buggered it.

[Garf3r]

Re: a quick spring related question

would bearing support not give him a extra inch to play with? i can give you a sp120 spring mate, its a guarder one

[rich1988]

Re: a quick spring related question

yea the bearing adds a bit but even so its still considerably longer, I may well be interested in the 120, how much would you want?

[Garf3r]

Re: a quick spring related question

give u it for nothing, its brand new mate, a bought a tune up kit, but just using the orginal spring, so jus pm me ur address n tht, n ill send it 2moz

[rich1988]

Re: a quick spring related question

really?! thanks very much ! could save me a lot of hassle :D let me paypal you a couple quid for postage at least?