FPS spring

[Vieler]

Is there a way to tell what FPS is by looking at the springs. Your help is greatly appreciated.

[dartguy43]

I found that all of my springs look the same and there is no length difference like the ones in your picture. I dropped them once and mixed them up and had no idea which one was which. The only way I could tell was to put them into my gun and shoot a few bb's over a chrono. Then I put them back in the proper packages. You might be able to tell which spring is which by squeezing and feeling for the hardest spring but this could be hit or miss. Hope this helps.

[lurkingknight]

nope... length is not necessarily a sign of strength.

Without a spring test rig you will just have to throw it into a gun and see. Barrel volume and cylinder volume also help determine final fps. There's other factors too like how quickly the air is delivered and air seal etc...

spring factors that also vary including length are irregular pitch or progressive springs that are easier to compress at one or both ends to start compression and then they progressively get stiffer towards the middle or other end of the spring. So just squeezing a spring may not give you a good answer.

Install one... pull it out.. label it. repeat