New Spring for Secutor Rapax XXI M4.

[Skullchewer]

So, I have locked my Secutor to Semi, for use as a DMR, but the FPS/joules is not what I want.
I am looking to get as close to 425 as possible, and at present am just looking to change the spring (As it has a quick change system).
But I have Spring confusion. 
The Secutor Rapax is essentially just an Ares SR25 with different internals, I believe. 
I am looking at this spring.
https://www.bespokeairsoft.co.uk/bespoke-airsoft-stel-tek-m150-aeg-spring-also-for-ares-striker

Will this fit? Or should I go with an Ares Amoeba Spring? 
https://a2supplies.co.uk/products/ares-amoeba-m100-spring

Obviously it doesn't NEED to be an Ares spring, just what is compatible.
Any advice greatly appreciated.

 

[ak2m4]

I'd avoid any chrome plated springs, generally lower quality Chinese piano wire that will lose FPS over time.  I'm not sure what the ARES springs are like.  With the SR25 you have a slightly longer spring space so I'm guessing it's a little different to regular AEG's in regards to power (can anyone confirm??).  Sadly you might have to buy a few different springs before you get the right one for 425.  Not taking into account compression issues as well...Often it's tricky.

How long is your current stock spring?

I've just got in stock some M140 springs:  https://www.ak2m4.co.uk/gearparts-aeg-spring-m140, or https://www.ak2m4.co.uk/gearparts-aeg-spring-m120

 

[Skullchewer]

Good question! I'll measure it and do some comparisons.

 

[Shamal]

Good question! I'll measure it and do some comparisons.

Ooer missus ?