Correct spring power and sized to use in my L96 clone, with Modify piston

[airsoftjunky]

My stock spring seems to have wore out and lost fps over the last three-ish years that I have used it. Its slowly been losing fps, till now its down from about 460 to approx 417. However, I am confused as to what spring to put in. Field limits are 475, and that's what I'm going for. I'm confused about:

(A) What spring do I need, and what size? 7mm, or 9mm? This is the piston I have currently installed:
http://www.airsoftparts.ca/store2/in...oducts_id=1096

(B)What size spring guide do I need? I've heard I need a 9mm for the stronger springs, but I don't know at what point, and if I get a different size spring, will it work with my current piston? I've never upgraded a spring or guide in a bolt action gun before.
I hope there's at least a few of you out there that can help me with my specific dillemna and have done the trial and error before me, and thanks in advance.

[KenTsui]

I can't say much about the Modify piston, but I have a PDI bolt and it looks like there are two sizes of springs. One that takes a 7mm spring guide (11mm OD, 8mm ID spring), and one that takes a 9 mm spring guide (13mm OD, 11mm ID spring).

The diameter of spring you choose will probably depend on the piston, and the spring guide obviously has to match the spring.

I hope that helps a bit.

http://www.x-fire.org/etop/bolt_sp.html
http://www.x-fire.org/etop/bolt_sp_thicker.html

[airsoftjunky]

A little. But the highest fps for the L96 shown there only goes to 450 fps. I'm looking for 475.

[chaz]

Why 475?

[Reignman]

I also ask. Just because the field limit is 475 doesnt mean you have to be at it. Its a limit, not a goal. Isn't ideal FPS around 380 or something? I haven't played with anything over 400 really .

[airsoftjunky]

Originally Posted by Reignman

I also ask. Just because the field limit is 475 doesnt mean you have to be at it. Its a limit, not a goal. Isn't ideal FPS around 380 or something? I haven't played with anything over 400 really .

My gun used to be more powerfull, and I can say from experience that more power equalls more range and ability to lift heavier bbs. My gun has slowly lost fps, and I've likewise noticed it losing range. While it used to be at 460 to 465 ish if I remember correctly, the loss of fps has definitely affected it negatively. If someone wants to tell me otherwise, I want them to show me their gun and results from it in person, as well as what set up they use. I've tried multiple different set ups in both sniper and aeg, and while yes, I agree, fps is not everything, it's still important imo for a bolt action sniper.

[chaz]

I know basr that shoot 400fps and outshoot ones shooting 500fps.
Anyway....

[KenTsui]

Originally Posted by airsoftjunky

A little. But the highest fps for the L96 shown there only goes to 450 fps. I'm looking for 475.

I believe those fps ratings on their site is off. I was aiming for 500 fps, and I got 550 fps with their SPR 250% (said to be 530 fps), even after cutting a few coils, I wasn't able to get it below 500. I ended up with the APS 240 (rated at 430 fps), and it ended up just under 500.

I'm using PDI bolt with sorbo, 6.05 barrel, and PDI chamber.

Edit: The fps I mentioned are calculated equivalent fps in .20. I actually used .43's on the chrono.

[airsoftjunky]

Originally Posted by KenTsui

I believe those fps ratings on their site is off. I was aiming for 500 fps, and I got 550 fps with their SPR 250% (said to be 530 fps), even after cutting a few coils, I wasn't able to get it below 500. I ended up with the APS 240 (rated at 430 fps), and it ended up just under 500.

I'm using PDI bolt with sorbo, 6.05 barrel, and PDI chamber.

Edit: The fps I mentioned are calculated equivalent fps in .20. I actually used .43's on the chrono.

So what spring would you recommend? I have much the same set up as you. PDI chamber, etc...

[airsoftjunky]

Originally Posted by chaz

I know basr that shoot 400fps and outshoot ones shooting 500fps.
Anyway....

I would be quite interested in the specs on this gun. Type of gun, as well as type of upgrades. The science of it all is fascinating.

[KenTsui]

Originally Posted by airsoftjunky

So what spring would you recommend? I have much the same set up as you. PDI chamber, etc...

Well, first you need to figure out which spring diameter to use. Then look at their chart and go with something a little lower than your target. If it's too hot, you can always cut a few coils. Or add washers if it's too low.