Reasons to change recoil spring

[yekcoh]

I know there are thousands of post asking about how often recoil spring should be changed and there is a s#!t load of answers, mostly opinions. 

Mostly, they do it so the gun functions reliably.

 

Here, I want to discuss something different about recoil spring:

 

1. The recoil dynamic AND Longevity of light recoil springs vs heavier springs

 

This is entirely anecdotal but in my experience or at least my theory is,

when a recoil spring wears out,

• it will shorten
• get less plastic,
• lose spring force

When the spring loses adequate resistances, the slide batters harder (more violent) during cycle causing the dot movement to become more sporadic.

Subsequently, it becomes harder to keep the dot movement in good vertical fashion. This becomes more prominent in lighter guns, polymer frames.

 

So as the spring wears, the recoil dynamic changes, forcing the shooter to adjust or change the spring.

 

This also prompts the following issue, do lighter recoil springs indeed have shorter lifespan?

I think if I were to use heavier factory spring, the spring life would hypothetically last like so. Note: the numbers are arbitrary.

 

new 17lbs recoil spring has 17lbs of force

after 3 thousand rounds force reduced to 16.5lbs of force

after 8 thousand rounds force 16lbs

after 15 thousand rounds 14 lbs

....

 

whereas a light recoil spring would undergo

 

new 13lbs recoil spring has 13 lbs of force

after 2 thousand rounds force reduced to 12.5lbs

after 4 thousand rounds force reduced to 11lbs

after 6 thousand rounds force reduced to 9lbs  at which point, the spring is too light to have consistent dot movement. 

 

I'm not concerned about spring not locking up consistently, gun will lock up during fire.

 

What do you think?

Edited June 18, 2021 by yekcoh

[Sarge]

I agree. I run 8# in my open guns. I tried 7# one season and found the gun would start hiccuping very quickly. If I kept the gun super clean it lasted longer but eventually would fail much sooner than an 8. I can run an 8 all season with very little gun cleaning.

One pound makes a world of difference 

[mpom]

Any info on going from a typical OEM 17# to a 13# wrt to the questions the OP raised? Would one expect more red dot movement and frame battering?

My very limited experience showed less gun bounce and perceived dot motion going from 17 to 13# recoil spring, single session, single handgun.

 

Mark

[yekcoh]

17 hours ago, Sarge said:

I agree. I run 8# in my open guns. I tried 7# one season and found the gun would start hiccuping very quickly. If I kept the gun super clean it lasted longer but eventually would fail much sooner than an 8. I can run an 8 all season with very little gun cleaning.

One pound makes a world of difference 

That sounds about right. 8 to 7 pound is over 12% difference so that’s not a small difference 
 

11 hours ago, mpom said:

Any info on going from a typical OEM 17# to a 13# wrt to the questions the OP raised? Would one expect more red dot movement and frame battering?

My very limited experience showed less gun bounce and perceived dot motion going from 17 to 13# recoil spring, single session, single handgun.

 

Mark

If you are referring to glock 17 to 13 should make the dynamic smoother, perceived. Falling below 10 is probably the turning point

[mpom]

Thanks, Yekcoh. Actually running a M&P, very similar platform.

Mark

[zzt]

I can't speak to plastic guns, but I can on 2011s and 1911s.  You have the 'correct' weight recoil spring when it, in combination with your mainspring and firing pin stop results in less secondary bounce, with enough dwell time to strip the next round, and no muzzle dip when returning to battery.  On my main Open gun that combo is an 11 lb. recoil spring, 19 lb. mainspring and a standard Cheely Open FPS.  On my backup gun it is 10 lb. recoil, 17 lb. mainspring and Cheely FPS.  Note these are aet up for 9mm major, 115 JHP @ 1470 fps.  Set up like that shooting minor is impossible.  I don't care, because the guns will live and run forever this way.

 

I built a twin 1911 Open gun for SCSA Open.  I built it for major and was asked not to shoot major at matches.  Do It now wears an 18 lb. mainspring, 7 lb. recoil spring and a FPS radiused all the way up to the firing pin hole.  I need 145 PF ammo to get it to run.

 

I'll also note that slide way and frame rail finish will partly determine what your recoil spring will be.  The first 2011 Open gun I built had the slide to frame fit milled to a light interference fit.  I burnished it in, but needed a 7 lb. recoil spring to get it to run with 172 PF ammo.  Over time, that loosened up and I used 8 and 9 lb. springs.  A manufacturing defect required warranty replacement of that frame.  The new one came back super, super tight.  I stoned a little, then lapped it in with 4000 grit diamond paste.  It is now super smooth and still tight.  There is zero play anywhere and it works with an 11 lb. recoil spring.  So no more machine finishes for me.

 

Back to the original topic.  It is time to change your recoil spring when dot/sight return is no longer normal.  Heck, they a $5.50 each so change them once a month or so if you are worried.  It certainly cannot hurt.

Edited June 20, 2021 by zzt

[loubob]

when working on spring tuning go to the range set up to do just that not i think this feels better i will leave it. Target with tape lines ,springs marked ,calm and focused 10yds 15 yds , group size ect . take your time do a good job it will give you confidence in your equipment. Observe the sight movement calmly .

[Kwontanamo]

has anyone messed around with the springs for a tanfo stock 3 extreme?

[Bakerjd]

On 12/16/2021 at 10:28 AM, loubob said:

when working on spring tuning go to the range set up to do just that not i think this feels better i will leave it. Target with tape lines ,springs marked ,calm and focused 10yds 15 yds , group size ect . take your time do a good job it will give you confidence in your equipment. Observe the sight movement calmly .

Getting ready to this very thing soon with the new open gun. Figuring out a load that makes PF and then will tune the gun for that load. 

 

For me I have the girlfriend video the shooting and have lines on the wall so I can see muzzle ride and dip. I don't draw, just hold the gun with my normal grip. I want to have as little variability in the test. 

[loubob]

Yes no need to draw elliminate unneccery actions , I also wonder about my grip but i start out with my best grip and then go to just firmly holding the gun. You get more muzzel rize with the lighter grip but the goal here is to get it smooth and straight. It would be cool to have one of those high dollar slow motion cameras.

[StefVanHauwe]

I replace the recoil and hammer springs preventatively in all my open guns at the end of the year/season. Ready for a fresh start of the new season!

[verla]

I replace the 9# recoil spring in my open guns after about 4500 rounds. Same for limited and 9mm guns.  Replace the magazine springs at least once a year or at the end of the season. Also replace the hammer spring yearly. This schedule seems to work for me.