bit of spring help

[Ells]

Hey, just looking for a quick bit of advice on what spring to get, and what make,

current set up;

madbull steel bore (229/ 6.03)
bearing spring guide
stock ics mx5-p spring an m100 (i think this is meant to give 330 or so, i cant see consistently the fps)
normal length piston 14 teeth
cylinder with 2 "teardrop" ports, about 1cm long each starting about 1 cm in from the rear. - ill be switching to non ported though.
11.1v 800mah 15-30C
SHS ultra high tourque

so the problem is, im currently putting out 380fps w/ .2 (+/- 1 fps), and 23 rps with an 11.1 at about 10 volts charge. Im thinking i'll need an m90 or SP80 (if guarder is still good), ideally i would like it at 350 fps bang on, but maybe probably around 340/345, but wondering if anyone could clarify on the spring strength, and any particular brands that are (currently) good, as I cant see anything from any recent threads. i was also wondering if anyone would know approximate RPS gain from dropping down a spring rating, and if i am likely to encounter any problem from doing so?

Thanks

[wilko129]

Re: bit of spring help

1. M90 would be right if you are getting that high fps out of your M100. Once it beds in it should get down to about 345/350 fps.
2. You will not have a noticeable rps gain because your motor is being supplied with enough amps already and is not under very much strain to begin with.
3. Don't change your cylinder for a non-ported one or you will make your rifle louder for no added benefit. The reason why you have a ported cylinder is because the barrel on your rifle is really short so needs far less air to fill its whole volume. Is your barrel the same length as the stock barrel?
4. make sure you stop using your lipo batteries when they get that low on charge because that is just above the minimum voltage before its starts to get damaged (3.3v per cell when under load or 3.7/8 when not under load).
5. As for brands i use SHS in all mine and they seem to work fine. i have used a Guarder one before and that was fine too but with springs its harder to gauge performance than it is with other parts.

[richw]

Re: bit of spring help

An M100 should be around 330 fps not 380 fps, how sure are you of it being a M100?

I'd go with a Guarder SP90, with good air seals that should put you on 325fps. If you believe you need that extra 25 fps you've already lost.

[wilko129]

Re: bit of spring help

An M100 should be around 330 fps not 380 fps, how sure are you of it being a M100?

I'd go with a Guarder SP90, with good air seals that should put you on 325fps. If you believe you need that extra 25 fps you've already lost.

They are guidelines mate which take into account the fact that most BBs guns have poor air seals. Adding tightbore barrels, having perfect air seals and heavier pistons/heads will boost your fps above the guideline amounts.

It is very possible that it is an M100 in his rifle given his tightbore.

[richw]

Re: bit of spring help

50fps is a lot to gain - I've only ever treated spring ratings with a decent air seal and a reasonable bore (6.05 ish) and I've been pretty lucky and everything I've fitted (in my limited experience) has landed about where I expected it to. I believe SP rated springs are rated with .25's just to confuse things!

I've read a few times about mis-packaged springs - notably SHS so you can't always rule that out either.

[Ells]

Re: bit of spring help

Thanks for the replies!;

@wilko -
1/2- Thats cool, I didn't know that about the motors, having it at its current rof, is perfectly fine for me, so thats pretty handy!
3 - I'll be switching to the non ported as i'll be using .3, so it'll need the extra volume, i think (according to some volume/ compression calculators- im not sure how accurate it is) that it achieves optimal momentum at about 220mm with a non ported cylinder with the .3s
4-This battery, was pretty much dead already, it was just to hand.
5- I figured it would be a bit of a subjective one, but i will look into this as well

@richw
I got the gun brand new, so unless they are advertising it incorrectly i am sure of the rating. i am however using a tightbore, and a bearing spring guide, and have a more or less perfect airseal. Assuming everything else is exactly the same, and one is no more effort nor cost over the other, i would take 350 over 325, as there would be no reason not to, but the fps was more a point that 350 is my sites limit, so bang on would be ideal, but due to fluctuations and external conditions, having it at 340/345 would be on the safe side,

[wilko129]

Re: bit of spring help

Thanks for the replies!;

@wilko -
1/2- Thats cool, I didn't know that about the motors, having it at its current rof, is perfectly fine for me, so thats pretty handy!
3 - I'll be switching to the non ported as i'll be using .3, so it'll need the extra volume, i think (according to some volume/ compression calculators- im not sure how accurate it is) that it achieves optimal momentum at about 220mm with a non ported cylinder with the .3s
4-This battery, was pretty much dead already, it was just to hand.
5- I figured it would be a bit of a subjective one, but i will look into this as well

@richw
I got the gun brand new, so unless they are advertising it incorrectly i am sure of the rating. i am however using a tightbore, and a bearing spring guide, and have a more or less perfect airseal. Assuming everything else is exactly the same, and one is no more effort nor cost over the other, i would take 350 over 325, as there would be no reason not to, but the fps was more a point that 350 is my sites limit, so bang on would be ideal, but due to fluctuations and external conditions, having it at 340/345 would be on the safe side,

3.The weight of your BB does not affect the volume of air you need to push it out the barrel pal. Think water in a pipe and all your changing is the amount of water, not the pressure pushing the water through the pipe. I just checked my sources and your barrel is just long enough to use a 3/4 ported cylinder which is the 2nd most ported cylinder amount. If you use a cylinder which has too high a volume it will just make your rifle really loud and make a popping sounds when it shoots due to the massive excess in air.

[Ells]

Re: bit of spring help

Cheers for explaining it! I've got to admit when it comes to working out things like this, i get pretty lazy and just rely on other people's guides , but anecdotally my ak74u, pretty much exactly the same set up, where it matters (barrel, fps, piston/cylinder head material, etc) but with a non ported cylinder is a lot louder! I went for a guarder sp85 btw, which should more, or hopefully less, put me on 350!

[wilko129]

Re: bit of spring help

No worries pal. Let us know if you have any more issues with it.