AR15 extractor spring life

[ny32182]

So a couple weeks ago, I took out an upper to shoot for the first time in years... This was an upper I bought roughly 9 years ago; I fired about 1100 rounds through it then with no issues at that time, and basically it has been sitting ever since.

A couple weeks ago I took it out and shot a couple hundred rounds, and toward the end of my session I started getting FTExtracts... the case would come off the extractor before ejecting and I would get a double feed.

When I got home I discovered that the extractor spring was basically completely dead. Like near-zero tension on the extractor. Honestly I'm amazed it was running at all.

Replaced with an extra power BCM spring, shot a couple hundred more rounds, back to normal.

So I started looking at my other extractor springs in guns I haven't shot in a while. They have more tension than the first one, but less than I remember them having when they were new. These are all basically safe queens for the most part.

Do these springs go bad just sitting for a few years? Is this a thing? I've never had any spring appear to go bad from just sitting before.

These are all from quality units, BCM, LMT, etc bcg's. I might just replace all of them for some cheap insurance.

 

[Wireman]

Not much information to go on. I would say that any type of spring in general does not suddenly go limp. The only way you could have a spring with little or no tension is if it has cracked or fatigued by continuous operation in spring bind (wrong spring, incorrect combination of parts, etc).

Lots of people believe that AR extractor springs need to be stiffened up in order to work correctly. Personally, I would start looking for other causes and stop blaming the spring for your trouble. If the current spring starts to fail, my first thought would be incorrect bolt timing.

Extractor spring gimmicks such as extra plastic bumpers and super strong springs are a band-aid. Mostly, the inserts are there to suppress spring resonance during full auto fire.

WM

 

[ny32182]

What more information would be needed?

Unfortunately I don't know much more than already stated. Gun was fine 9 years ago, and I certainly would have noticed if the spring was excessively weak at that time. Last week, extractor spring was DEAD. Literally nothing happened in between.

Spring was not cracked. I replaced everything under there; spring, o-ring, and the little post.

 

[briansmithwins]

Lots of people believe that AR extractor springs need to be stiffened up in order to work correctly. Personally, I would start looking for other causes and stop blaming the spring for your trouble. If the current spring starts to fail, my first thought would be incorrect bolt timing.

Extractor spring gimmicks such as extra plastic bumpers and super strong springs are a band-aid. Mostly, the inserts are there to suppress spring resonance during full auto fire.

I agree that springs should not fatigue when just being stored. But lots of companies make AR parts with very little/no quality control.

I think the real problem is that the AR15/M16 extractor and spring design worked for the original 20" rifle. The extractor had enough tension and grip to reliably extract when clean and in good conditions.

But then people wanted shorter versions, and the basic design wasn't changed to accommodate the fact that moving the gas port closer to the chamber and chasing the gas port size changes the forces on the fired case and bolt.

What should have happened is that the bolt was redesigned to accommodate this. What actually happened was that the 20" bolt design was just dropped into the shorter rifles.

I've run a HD extractor spring with o-ring on a 20" rifle with no problems. I actually haven't seen an AR that had too much extractor tension to work. I have seen a few that didn't have enough extractor tension to reliable extract*.

BSW

*Naturally, this happens during a rifle match, when there are people around to watch you struggle with clearing a FTExtract stoppage.

 

[ny32182]

When I say the spring was dead, I mean that literally I didn't even have to push down on the extractor to push the pin out. It just slid right out with no effort at all, as if there was no spring in it. I seriously doubt it would have been any different in a 20" rifle.

It is a 10.5" carbine though, so yeah, lots off port pressure.

 

[briansmithwins]

10.5" carbine

Yeah, that's going to stress some parts. I use the BCM HD extractor springs with 0-rings and I haven't had any problems with them. then again, I also don't have that short of a upper on any AR I own.

BSW

 

[ny32182]

I think that this spring was just a bad part and fatigued while sitting compressed for a few years. I guess I'll have to wait 9 more years to see if the BCM exra power spring does the same, but I will say that it is a lot stiffer than any stock extractor spring I have ever seen.

 

[Onmilo]

What more information would be needed?

Unfortunately I don't know much more than already stated. Gun was fine 9 years ago, and I certainly would have noticed if the spring was excessively weak at that time. Last week, extractor spring was DEAD. Literally nothing happened in between.

Spring was not cracked. I replaced everything under there; spring, o-ring, and the little post.

Not a word on mention to whit the ammunition one was using,,,

 

[ny32182]

Mix of Radway Green M855 spec and 55gr reloads then and now.

 

[Quentin]

I think that this spring was just a bad part and fatigued while sitting compressed for a few years. I guess I'll have to wait 9 more years to see if the BCM exra power spring does the same, but I will say that it is a lot stiffer than any stock extractor spring I have ever seen.

Well I can say my 2010 BCM upper is perking right along with its original extractor spring. So they're good for six years, at least with fairly light use. I do have spare, unused, BCM springs but don't notice any difference whether used or unused. I was thinking of replacing "just in case" but now why not go for 9 years! If it ain't broke why fix it.

I did have an extraction issue in another AR (surprisingly a Daniel Defense!) and a BCM extractor/spring kit solved it. That BCM replacement spring also has been fine for 6 years. I suppose a weak spring occasionally makes its way into an AR here and there. The DD extractor looked good and the spring wasn't unusually weak but I'd never trust them.

 

[agtman]

Civiy recreational weekend use vs. hard rocking mil-use. L.E. is somewhere in the middle, depending.

Good to always have spares regardless.

Stay thirsty dudenals.

 

[MistWolf]

The extractor spring is one of the many small details why the Colt is a much better choice than the "Just As Good As" brands. Colt has long since fixed the problem of the extractor spring in the M4. The most current Colt spring has 5 coils, copper colored and had a black polymer insert. The O ring was a temporary fix and if used with the proper spring, will result in too much pressure on the extractor

 

[ny32182]

Sure enough I just opened up a colt (unfired, several years old) and it has a copper colored spring and no o-ring. I would not say the extractor tension was remarkable either way.

 

[goon]

It was probably just a bad spring. I also had a problem once with a new upper giving me FTE's after about 200 rounds. It's irritating, but these things are cranked out by the tens of thousands, so eventually there will be some that don't get proper heat treating.

But at least they're cheap to replace and available. And easy to replace... replacing an extractor spring on an AK or SKS is a more challenging task.

 

[entropy]

It's not like they are expensive or hard to put in.....

 

[briansmithwins]

The O ring was a temporary fix and if used with the proper spring, will result in too much pressure on the extractor

What kind of failure results from excessive extractor spring pressure?

BSW

 

[rcmodel]

The extractor couldn't snap over the case rim when chambering slowly in stealth mode??

rc