Combining multiple Recoil Springs

[MuayThaiJJ]

Hey guys,

 

For the life of me I cannot find the thread on this, I thought it was on Enos. I may be mistaken.

Anyways, there was a thread on guys using different # recoil springs to make a sort of Frankenstein DIY variable spring. Some even use 3 different springs.

 

I have a load I really like, my STI loves it but my Tanfo doesn't quite cycle it. I tried 8# Patriot Defense RS and a 7# Wolff long slide spring.

I am thinking of trying a 6# Wolff long slide spring and clipping 3/4 of it, then clipping 1/4 of a 8# spring to make my own variable spring.

 

Any insights?

[Russty]

Springs are cheap, right? Go for it.

[ChuckS]

6 hours ago, MuayThaiJJ said:

Hey guys,

 

For the life of me I cannot find the thread on this, I thought it was on Enos. I may be mistaken.

Anyways, there was a thread on guys using different # recoil springs to make a sort of Frankenstein DIY variable spring. Some even use 3 different springs.

 

I have a load I really like, my STI loves it but my Tanfo doesn't quite cycle it. I tried 8# Patriot Defense RS and a 7# Wolff long slide spring.

I am thinking of trying a 6# Wolff long slide spring and clipping 3/4 of it, then clipping 1/4 of a 8# spring to make my own variable spring.

 

Any insights?

A cut in the middle of a coil spring is, in my opinion, asking for some sort of binding/stacking failure. As the poster above pointed out, springs are cheap, just buy a variable. (And you may want to chrono that load if you haven't done so yet  )

[Yeti]

Maybe you are reinventing the wheel.  Your load is too light for 8# recoil?? 

Could the problem be the load?  Just saying.  

[MuayThaiJJ]

It's 3.7gr Titegroup with 125gr bullet, PF: 130, 1050fps

It cycles nice with my shorty STI but the Tanfo with compensator eats up so much power.

 

I can't find a variable 7# Tanfo spring.

Anyways, I ordered a 6# long slide spring - I'll try it. And I'll try clipping a coil at a time with the 7# longslide spring.

[Jim Watson]

If you stack two different springs, you will have to have a washer or spacer between them so they don't screw into each other.

[Amra86]

When you stack springs you create a much lighter spring. A 6# and 8# stacked spring will egual a 3.4# spring. 

[Jim Watson]

How do you allow for the stacked springs having been clipped to fit the space, assuming he starts with two regular recoil springs of different rating?

 

I have read that cutting a coil spring actually increases its rate, but I am too far from my Engineering Mechanics class to figure it out.

Edited May 19, 2021 by Jim Watson

[ChuckS]

4 minutes ago, Jim Watson said:

I have read that cutting a coil spring actually increases its rate, but I am too far from my Engineering Mechanics class to figure it out.

Yup, it was just pointed out in another thread.

 

https://www.acxesspring.com/compression-spring-rate.html#:~:text=To know your compression spring,force per inch of travel.

 

But the pre-load does decrease so when you tug on the slide it feels different but when the spring compresses it obeys the physics of the modified coil count. 

 

So, with the modified spring, the slide will open with less resistance but the overall travel may actually be reduced.

 

Individual springs will add as Amra86 pointed out but the individual springs may not have the properties you think they have.  

[CocoBolo]

Engineering 101 duct tape or WD 40, I'll go with if it isn't broke don't fix it, or if brute force isn't work you just are not using enough.  That load sounds a little rodent methane to me, I'd add a couple tenths and see if it resolves the problem, max load is 4.4gr.   

[Aircooled6racer]

Hello, try 4.1 grains of Tite Group. It should be good to go. Thanks, Eric