Airsoft Sniper Forum banner
61 - 80 of 90 Posts

·
Registered
Joined
·
2 Posts
Hi, your JC posts are helping me a lot.

Do you have tips on where to cut an irrigular pitch spring ?

I cut mine in the coils that are more spaced as I wanted to keep the dense coil part for my spring guide. The result is that I lost JC. ( the spring is 10cm longer than my cylinder at rest )

Are asymmetrical spring a bad choise to "easily" optimise JC
thx!
 

·
Registered
Joined
·
224 Posts
NOTE: If your fps is just over your club limit, do not cut the spring. Instead, wrap solder around the piston (If you have the space to do this) and then use a little electrical tape to hold it on. This will slow the piston down and then you should be under your limit. You can remove the solder once the spring has worn in.

To make your FPS more consistent and to give your spring longevity you are best to choose a spring that is bigger than what you need and then cut it down. If done right the spring, once cut, should only just be compressed a little in the cylinder. For example, in my VSR10 I use a Laylax SP190 spring that can produce really massive amounts of energy (way more than I need). I cut a few coils off the spring so that it is only just compressed about 10mm when the gun is not cocked. This means that over the period of time between games the spring does not lose its rigidity.
Also once the spring does start to wear down you can make a little round washer/spacer to fit behind the spring on the guide to put the fps back up a little. With weaker springs you will need to put in a bigger spacer to make a reasonable difference but with stronger springs that have thicker wires, you will only need a little spacer.

Note: When choosing the spring, only get one that is about 50-70fps above your desired rating that you wish for. If you go too big then you will have to cut more coils off the spring and then the spring may fit loosely in your cylinder and may bounce around. Also, before cutting the spring, leave it in your cylinder for 2-3 weeks. This will mean that the initial main loss of energy should have happened and the spring should have stabilized more.

Another interesting note is that manufacturers often test the "M" ratings on springs with a short inner barrel of 220mm x 6.08mm. So if it says "M150" then it is most likely 492fps (150 meters a second)using 0.2gm bb's with a 220mm long inner barrel. Often in your own setup, the fps will be higher as you may have a longer inner barrel

Here is a rough guide for spring ratings once they have worn in.
M90 = 270-285fps
M100 = 300-315fps
M110 = 330-345fps
M120 = 360-375fps
M130 = 390-405fps
M140 = 420-435fps
M150 = 450-465fps
M160 = 480-495fps
M170 = 510-525fps
M180 = 540-555fps
M190 = 570-585fps
Or
SP130 = 445fps
SP140 = 480fps
SP150 = 510fps
SP160 = 545fps
SP170 = 581fps
SP180 = 615fps
SP190 = 650fps
Or
PDI 100% = 290-300fps
PDI 120% = 320-330fps
PDI 140% = 335-345fps
PDI 150% = 350-360fps
PDI 170% = 395-405fps
PDI 210% = 420-430fps
PDI 240% = 450-460fps
PDI 270% = 480-490fps
PDI 300% = 520-530fps

One good thing to note is that Laylax VSR10 springs will also work in a Maruzen/WELL L96 but you may have to drill out the piston a little. Most aftermarket L96 pistons will fit a VSR spring straight off without modification.
Even though Laylax springs cost a little more, I really rate them as they last a lot longer than most other springs.

How to cut a spring
Step 1: Cut the spring with side cutters or hack saw. Normally 1 coil will be about 20fps on a M130 spring. The bigger the spring the more FPS a coil will be. So a M190 spring is normally about 30 fps per coil. (This is only a guideline as not all brands or springs are the same). If you are wanting to take off 2 coils then cut just before 2 coils. So cut about 1 and 3/4 coils.





Step 2:Heat the spring and flatten the pointed part that sticks out.



Step 3:Grind any sharp points



Finished



Also note that spring lengths can effect joule creep.
If a spring has been cut to be the same length as the cylinder, the spring will apply not much force when the piston has reached the end of its travel because the spring will be fully extended. This will mean that the piston will travel fast at the start of its movement but then only gain very little acceleration after the initial burst.
When making a JC rifle, you want the piston to travel slow as the start of its movement and fast at the end.
Great post!
 

·
Registered
Joined
·
224 Posts
Has anyone worked out a formula how many coils per fps. Does the fps divided by the number of coils on a spring work in determining the amount fps per coil? Or is it just trail and error? Cut one coil, throw it back in test the fps then repeat the procedure until you get close to where you want to be?
So to get to 470-485 fps would a 150 spring work better than a 160 with one coil cut off?
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #64 ·
It is really just trial and error as some springs are thicker that others as well as longer than others.
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #65 ·
I would use the M160 and put weight on the piston. That is way better than cutting a coil off.
To put weight on the piston, just wrap solder around it and the hold it on with a layer of electrical tape.
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #69 ·
Oh. I thought you had some way of reducing fps with adjuster rings.


Yes, they are fine to use to increase fps. If you make some, just make sure not to make them that long that the trigger sear will not catch. Also, make sure that they will fit into the piston nicely.
 

·
Registered
Joined
·
224 Posts
How long do non cut springs typically last? Also would a M160 work for a new JG BAR10 and how much FPS would that give me?
Is this guide right?
Most people are telling me a M150 will be shooting about 520 fps?
M90 = 270-285fps
M100 = 300-315fps
M110 = 330-345fps
M120 = 360-375fps
M130 = 390-405fps
M140 = 420-435fps
M150 = 450-465fps
M160 = 480-495fps
M170 = 510-525fps
M180 = 540-555fps
M190 = 570-585fps
 

·
Registered
Joined
·
969 Posts
It depends on the brand. M150 is typically ~492 fps once it breaks in.

Buy more than what you think you'll need. Leave it cocked overnight. Then chrono. If it's still high then either cut the spring, weight the piston, or both.
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #72 ·
It is an approximation. It depends on brand of spring and barrel length too.
The fps rating are pretty accurate though. Normally you multiply the M number by 3.28 and that will give you the fps when new (give or take 20fps). So 492fps. Then once it has settled it will be less. But it is not an exact science as longer barrels will give you more fps and shorter barrels will give you less fps. If you have a barrel of about 360mm, that would be about the average.
 

·
Registered
Joined
·
224 Posts
It depends on the brand. M150 is typically ~492 fps once it breaks in.

Buy more than what you think you'll need. Leave it cocked overnight. Then chrono. If it's still high then either cut the spring, weight the piston, or both.
Thanks

I will probabaly go with a AA M150 and cut two coils off. That should give me about 475 fps after breaking it in?

I am installing a 430 / 6.01 inner barrel which I assume would also give me a 20-30 fps boost.
 

·
Registered
Joined
·
224 Posts
It is an approximation. It depends on brand of spring and barrel length too.
The fps rating are pretty accurate though. Normally you multiply the M number by 3.28 and that will give you the fps when new (give or take 20fps). So 492fps. Then once it has settled it will be less. But it is not an exact science as longer barrels will give you more fps and shorter barrels will give you less fps. If you have a barrel of about 360mm, that would be about the average.
Thanks
I am installing a 430 / 6.01 inner barrel which I assume would also give me a 20-30 fps boost.
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #75 ·
It may give you about 10fps extra.
Add weight to the piston to bring the fps down. Wrap solder around it and hold it on with a layer of electrical tape. Then oneday when the fps does drop too low (Once worn in), you can take off the weight and the fps will go back up. So you get twice the life out of your spring.
 

·
Registered
Joined
·
224 Posts
How long do non cut springs typically last? Also would a M160 work for a new JG BAR10 and how much FPS would that give me?
I think a m150 would be better if your field limit is under 550 fps. Over 550 fps, [Sweden etc.] you could use a M160. Tight air seal and tight inner barrel will also increase FPS which is why each person you ask with the same spring has a different FPS.

Note: If you install a M160 into a stock new JG Bar -10, the trigger / piston will break. You have to upgrade the trigger/ piston first.
 

·
Registered
Joined
·
224 Posts
NOTE: If your fps is just over your club limit, do not cut the spring. Instead, wrap solder around the piston (If you have the space to do this) and then use a little electrical tape to hold it on. This will slow the piston down and then you should be under your limit. You can remove the solder once the spring has worn in.

To make your FPS more consistent and to give your spring longevity you are best to choose a spring that is bigger than what you need and then cut it down. If done right the spring, once cut, should only just be compressed a little in the cylinder. For example, in my VSR10 I use a Laylax SP190 spring that can produce really massive amounts of energy (way more than I need). I cut a few coils off the spring so that it is only just compressed about 10mm when the gun is not cocked. This means that over the period of time between games the spring does not lose its rigidity.
Also once the spring does start to wear down you can make a little round washer/spacer to fit behind the spring on the guide to put the fps back up a little. With weaker springs you will need to put in a bigger spacer to make a reasonable difference but with stronger springs that have thicker wires, you will only need a little spacer.

Note: When choosing the spring, only get one that is about 50-70fps above your desired rating that you wish for. If you go too big then you will have to cut more coils off the spring and then the spring may fit loosely in your cylinder and may bounce around. Also, before cutting the spring, leave it in your cylinder for 2-3 weeks. This will mean that the initial main loss of energy should have happened and the spring should have stabilized more.

Another interesting note is that manufacturers often test the "M" ratings on springs with a short inner barrel of 220mm x 6.08mm. So if it says "M150" then it is most likely 492fps (150 meters a second)using 0.2gm bb's with a 220mm long inner barrel. Often in your own setup, the fps will be higher as you may have a longer inner barrel

Here is a rough guide for spring ratings once they have worn in.
M90 = 270-285fps
M100 = 300-315fps
M110 = 330-345fps
M120 = 360-375fps
M130 = 390-405fps
M140 = 420-435fps
M150 = 450-465fps
M160 = 480-495fps
M170 = 510-525fps
M180 = 540-555fps
M190 = 570-585fps
Or
SP130 = 445fps
SP140 = 480fps
SP150 = 510fps
SP160 = 545fps
SP170 = 581fps
SP180 = 615fps
SP190 = 650fps
Or
PDI 100% = 290-300fps
PDI 120% = 320-330fps
PDI 140% = 335-345fps
PDI 150% = 350-360fps
PDI 170% = 395-405fps
PDI 210% = 420-430fps
PDI 240% = 450-460fps
PDI 270% = 480-490fps
PDI 300% = 520-530fps

One good thing to note is that Laylax VSR10 springs will also work in a Maruzen/WELL L96 but you may have to drill out the piston a little. Most aftermarket L96 pistons will fit a VSR spring straight off without modification.
Even though Laylax springs cost a little more, I really rate them as they last a lot longer than most other springs.

How to cut a spring
Step 1: Cut the spring with side cutters or hack saw. Normally 1 coil will be about 20fps on a M130 spring. The bigger the spring the more FPS a coil will be. So a M190 spring is normally about 30 fps per coil. (This is only a guideline as not all brands or springs are the same). If you are wanting to take off 2 coils then cut just before 2 coils. So cut about 1 and 3/4 coils.





Step 2:Heat the spring and flatten the pointed part that sticks out.



Step 3:Grind any sharp points



Finished



Also note that spring lengths can effect joule creep.
If a spring has been cut to be the same length as the cylinder, the spring will apply not much force when the piston has reached the end of its travel because the spring will be fully extended. This will mean that the piston will travel fast at the start of its movement but then only gain very little acceleration after the initial burst.
When making a JC rifle, you want the piston to travel slow as the start of its movement and fast at the end.
Hello 1tonne,
I just got my AA trigger set, spring guide and M-150 spring in the mail today.
I am planning on cutting two coils off of my M-150 spring before installation and then test the FPS. I figure after worn in it would put me under 480 fps. [My field limit] If not, I can cut some more.

I was just reading a posting on another forum which I am cynical about but I thought I would confirm with you. This posting claimed that you cannot cut sniper springs as opposed to AEG springs, because sniper springs are linear and you will possibly wreck the spring if you cut it?
Considering you seem very knowledgeable and you have a excellent post on how to cut springs, I am assuming this is more airsoft misinformation.
Thanks again for your help. I am going to use your guide to cut my spring this week.
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #78 ·
You can cut sniper springs.
But in your situation I would not. Just purchase some solder and wrap it around the piston to slow it down. If you take 2 coils off of an M150 you will most likely end up with only around 450-460fps. Just add weight to the piston. Then once the spring has worn in, take the weight off.
 

·
Registered
Joined
·
224 Posts
I know I should have listened!:yup: You were right!
I just cut two coils off my new Action Army M-150 spring and I went from 505 fps to 468 fps. My objective was 480. Oh well, at least I am within the limit now and can always buy another spring in a few months.

How about a washer behind the spring guide? Have you tried that?
 

·
Registered
Joined
·
5,534 Posts
Discussion Starter · #80 ·
You can do that but don't make the wash/spacer too long otherwise the piston sear will not catch onto the trigger sear.
 
61 - 80 of 90 Posts
Top