A Colt buffer spring costs $10 from brownells.
And only 7 bucks from SAW.
Someone posted that their LMT springs wore out fast. I have two factory LMT lowers that each have about 2500 rounds each. One runs an H buffer and the SBR has a H2 buffer. The one with the H buffer measures in at 10 3/4 and the one with the H2 measure 10 1/4…wonder if these are weak springs.
What I can’t figure out is why every “expert” on this board doesn’t specify a bone stock Colt SP1? After all, it was surely perfect, right? And what’s up with those idiots at NSWC Crane? How could they possibly know something about the M4 that Colt doesn’t? :rolleyes:
It should be abundantly clear by now with the plethora of reputable units and companies tweaking the science of the black rifle, that there’s room for improvement. By the same token, it should be readily discernible that the science of the spring has advanced since the days of leaf springs in Colt SAA’s. There have been tweaks and adjustments to gas port sizes, gas tubes, BCG’s, buffers and yes, spring lengths and tensions.
Compression coil spring failure rates increase exponentially as they loose tension. Not so much because of failed tensile strength as the subsequent coil bind. Coil bind dramatically accelerates the onset of failure. Combating coil bind is either a function of replacement or increasing the life cycle of the spring. Either will work, but not everyone studiously logs the exact number of rounds on a spring or performs routine measurement and inspection of their springs. A springs overall length is a good, but not infallible measurement of its life expectancy. Creating a spring with a longer life cycle that’s produced with rigid quality control and exceptional consistency is a good thing.
Also consider that not every AR pattern carbine is identical to every other AR carbine. With so many variations in components, specs and accessories, it’s plausible that the exact spring/buffer/BCG combo for perfect function in one may choke in another. If the owner has performed due diligence in testing their assembly of quality components for reliability and durability, who are you to say they’re full of shit?
Of course if your name ends in EngD, PhD and you want to prove me wrong, I’m more than willing to eat my words! 
You’re probably answering your own question. If the configurations differ, likely the dwell time of the bullet and lock time of the action do as well. One may have higher stress impulses on the spring, which will cause it to fail more quickly. Additionally, springs are made in batches and not every batch is identical. There will likely be a median specification range for an acceptable spring by contract standards before the purchaser rejects a batch (I’ve discussed the subject with a handgun production manager that once rejected a spring batch. The rejected batch was 5,000 springs.)
Simply saying X,Y or Z manufacturers produce reliable springs is a crutch to throw a spring in a gun and forget it. While some springs in a firearm may function with low stress, springs such as action springs get heavy punishment. It’s wise to regularly inspect them and replace them at the first sign something isn’t right. Too many people wait till a spring fails to replace it.
Do you wait for the oil in your car’s engine to fail before you replace it? Just because I specify Mobil 1 engine oil doesn’t mean I’m not going to inspect the oil itself when I check the level on the dipstick. The same goes for my firearms action springs. Premature failure of a spring may mean a bad spring, but it may also point to something wrong with another part in the gun. If you know and understand the how and why of your gun’s firing cycle, it can tell you when something isn’t right before it fails. Catastrophic failure isn’t always avoidable, but sometimes it’s detectable before things go tits up.
Big +1
It’s advancing the art. We’re not exactly talking about Tapco springs here, either.
Disclaimer: I have had very positive experiences with Brownells, Wolff, Springco, and Tubbs buffer springs. I’m currently running a Springco Blue in my BCM 14.5" middy to great effect. I’ve A-B’d it with a std SS buffer spring and the difference in the recoil stroke is marked, especially when shooting while moving perpendicular to the target.
The problem is that what you imply is not what is happening. You’re implying that people are out there swapping out parts, scientifically tracking the changes from the old parts to the new, all because they established some deficiency in the stock part.
This is not what is happening.
What is happening instead is that some dude gets a new gun sitting in the safe. He’s anxious to tinker with it. Rather than get out there and shoot it (ammo, magazines and range fees get expensive, plus there’s that whole “going outside” thing that’s not so much fun) he starts monkeying with it. He posts a thread on free-float rails and people ask him to tell them what’s wrong with the stock handguards. Nuts, stymied. So he posts a thread on which new stock to buy, and people ask him to tell them what’s wrong with the one that came on the gun. Damn. Jerks. Finally he stumbles on the spring, and rather than get the same old response he got in the other two threads he thinks “well it’s only $20, I’m just gonna order it”. Only to find out that he didn’t have the magical combination of parts that this new spring was designed for and starts having malfunctions. This, of course, only if he finally gets out to the range.
This is not, for the record, and indictment of the OP or of anyone in particular that posted in this thread. What it is instead is a commentary on the whole "range as laboratory (at best, assuming the person ever shoots their “improved” gun at all) that seems to be the trend of late. Change this insignificant part to improve this function or handling of the gun to improve times on this one particular drill. Utterly useless.
Do I think everyone should just own an SP1? No, but I do think people should buy a basic gun, go shoot it, and find the shortcomings for themselves rather than making changes that the internut says they should. Ultimately, however, it’s their money and as long as their not at one of my events being unsafe or standing next to me on the line holding up a class with their malfunctions, I’ll happing shoot rings around them with my 6933 wearing MOE furniture and an Aimpoint. :sarcastic:
Really not sure if this was all directed at me :blink:? Yes I change the oil in my car and every 5-6k miles because every 3k is a freaking joke and myth anymore (yes there have been improvements in oil since the 3000 mile rule of thumb, probably like their have been improvements in spring technology and metals since the 50’s).
I have learned the replacement length for a buffer spring is about 10 1/8 inch, at which point it time for a new one. I only made the comment because 2500 rounds does not seem like much at all and that a GI spring should last a few more than that. Someone else mentioned having to replace their factory LMT springs early as well, trend…to little information to tell but it is interesting.
I never said anything about either gun malfunctioning, and they don’t, just my own observations about the spring length and the recomended guide to replace them before malfunctions start. I never said I was going to run out and buy a fancy spring, on the contrary I was just going to by a factory colt spring from SAW. Of course my SBR has shorter dwell time then my 14.5, that has been proven so to say something deeper is wrong with the gun (when there is nothing wrong) is laughable.
I went and looked back for that thread.
https://www.m4carbine.net/showthread.php?t=63223&highlight=springs
I was unaware of 17-7 PH treatment for SS springs at that time.
Also now that I think about it I have never had a spring ever go out that fast even in my younger days owning used cheap clone pistols that I know damn well have never had the springs replaced.
I have seen reports of others about LMT buffer springs going out around the 2k mark I have seen couple of reports about the vltor a5 buffer spring not lasting. I will order a Colt rifle length buffer spring from SAW when ever I get around to changing to the A5 system. I will give it a fair try if it lasts then I will be happy to stick with it.
I think you are absolutely spot on there. Case in point being Todd K’s post in this thread - having had rifles returned needing “fixing” due to them having an extra power spring in there. To me, that is the owners being either a; absolutely full retard (swap spring, rifle all of a sudden no work? Hmm, Must be rifles fault, send back to Noveske!) or b; people who are gun owners not shooters, they mess with the rifles before even trying them out and shoot them only long after they swapped the spring and others parts and have no idea what is causing the problem…so back to the manufacturer it goes.
I wouldn’t advocate Sprinco (or any other aftermarket stuff, springs or otherwise, come to that) for the uninformed masses; but for individual people who shoot for a hobby and/or work combined with regular range time and training to prove reliability, and who have just the tiniest ability to troubleshoot - they can be a great and cost effective improvement over stock (and as has also been brought out in this thread…“stock” springs are by no means consistent; batch to batch and manufacturer to manufacturer, they vary in length and longevity).
For anyone who has not read it, I would recommend taking a look at Mike Pannone’s article which includes discussion on sensible reliability upgrades (inc Sprinco springs).
- Again, a disclaimer - all or none of anything mentioned may or may not work, so it is ultimately up to the individual to test it - so it is for informed and capable shooters only, not merely gun owners.
What does Crane have to do with any of this?
Also consider that not every AR pattern carbine is identical to every other AR carbine. With so many variations in components, specs and accessories, it’s plausible that the exact spring/buffer/BCG combo for perfect function in one may choke in another.
Circular argument. If there wasn’t all these aftermarket snake oil “improvements”, there wouldn’t be the need for more aftermarket “fixes”
That depends on how you define “stock”
If you buy a genuine USGI spring, then you have no variation to worry about. That is how I define “stock”
Most people define “stock” as the standard spring that all brands come with. Obviously there can be variation here because most brands are junk.
Yup, and if someone has a system of chicken blood, hemp string, and elephant boogers that works for them for their purposes for thousands of rounds, then nobody should be telling them different. But they should also have the self-confidence to keep on using what they’re using and know works for them regardless of what anyone else tells them should be working.
I agree with everyone and yet I disagree as well. It was designed as a system so upgrades must all be done as a system and there is plenty of room for upgrade in different areas. If you install a D-ring with a super extractor spring, you will need a stronger main spring, if you don’t see this then don’t mess with it. A gun, to me, is better if it is over gassed, running a heavy ass buffer and atleast an o-ring to help extractor slipping. You see more short strokes that cause a mag malfunction diagnosed as a mag malfunction, if you’re actually using the case deflector you better be shooting the most low powered ammunition you hope to ever encounter in your life. Otherwise keep it overgassed and if it is just too much step up buffer mass. Momentum and conservation of energy are the things we need to examine in a weapon that is given an immense amount of energy by the gas system and is required to perform the actions it needs before locking up to do again. A H2 buffer and the carbine spring are the shit, but those main springs really get weak fast, they will continue to operate on a 30 rd magazine well past their noticeable weakness. High Cap drums have problems with the weak weapons before this point because they require more operational energy because of the additional force on the bolt group.
If you’re going to increase spring rate of the main spring, think more gas and heavy buffer to balance system. When it comes down to saying well Colt does this, the GD&T of the TDP is amazing, Colt does well. Most AR makers just look at their testing criteria and build for it. A precision shooter shooting reloads might prefer an undergassed gun as it cycles and he doesn’t care, if he’s shooting hot loads and its brass ejection is in a weak area, then it will experience issues with ammunition in life.
I have the option of using whatever, as I just do R&D mostly, I don’t care who made what, I check out how it works, if you think you have too much spring on the extractor/ or ejector, with a full magazine give it just a little travel to lockup and see if it stalls. If you’re not locking a magazine back then holy cow you need to see that thing on high speed and see how it is just not completing a stroke. Ejection angle got me recently though, because forward ejection can be a short stroke if the gun is using the case deflector. If you are concerned about your gas rings not being in line to make a stong enough stroke, you have other issues, I think mine is so gassed it will run with no rings.
The DI AR system is a real nice thing but it is a little sensitive so sticking to the mil spec is a great suggestion because it works as a system. I recently just got some new gas tubes that don’t melt and I get to put up the ultimate challenge against the piston guns now because that was the one failure point in a DI system being used as a machine gun. It’s a goofy thing I know and well past cookoff but the DI system still does well in this arena, a little dirty but very functional.
It should be obvious by my two posts that I believe everyone should shoot theirs until reliability is proven before relying on it for more than punching paper. Any good quality basic carbine is going to do better than the average operatior, but that doesn’t mean it’s “perfect”. I’ve seen 1911’s that went bang every time, yet frequently (as in half or more) push feed. There’s a distinct hitch in the feeding process. Is the gun reliable? Yes. Is it optimally tuned? No. The same goes for AR systems. My KISS carbine has a std. Colt spring. My Rogue Hunter has an A5 system (watching the spring closely), and my 11.5" M16 has a red Sprinco and H2 buffer. It didn’t start out with that configuration, but after much testing it seems to operate optimally with that setup. This was confirmed with a test consisting of 800 rounds with no lube, followed by an additional 300 rounds with lube before cleaning. Not only was function 100%, but indications are that the system is well balanced with this setup.
I’m not advocating immediately changing out otherwise perfectly good springs before firing the stock setup. I am advocating knowing your particular gun and understanding what makes it tick. If it isn’t functioning well within the parameters, then I do advocate tuning it until it does. I guess what I’m saying is that merely acceptable isn’t acceptable to me.
I took your post as questioning whether your springs were ok, which they probably are (for now). I’m merely suggesting that it’s good to keep an eye on the system and listen to what it may be telling you before it pukes. It may never puke and you will likely never need something besides a factory Colt spring. I’m not saying anything is wrong with your gun, so disregard.
Seriously? Apparently the first part went over your head, because your response to the second part could be construed as equating the SOPMOD to a “snake oil improvement”. There’s nothing wrong with a stock SP1, SOPMOD, Knights/Noveske/Daniel Defense etc. “improvements”, and there’s nothing wrong with a better spring IF your particular setup would benefit from one. You’re obviously a Colt fanboy and there’s absolutely nothing wrong with that, so carry on! I just think you’re a little absolutist that anything other than your personal choices are somehow substandard. I don’t think anyone here is recommending changing over to UTG/TAPCO/CAA type stuff.
I think slightly overgassed is superior to attempting a delicate balance or undergassed. However, excessive gas like you seem to prefer is ultimately going to cause more issues than rapid spring wear. I don’t want the absolute softest shooting AR because it’s going to be undergassed and too close to the edge of it’s operating parameters. Neither do I want a carbine that recoils hard as it beats itself to death. Balance is the key and for me, the fulcrum point should be just on the high side energywise. JMO, YMMV
The SOPMOD program did not alter the internal components of the weapon.
While we are talking about springs, this was discussed not too long ago and the thread is linked above. Might be worth another read as there is some interesting information in there provided by rsilvers.
I have brand spanking new, Springco red buffer springs that I will sell for $20 shipped. Disclaimer: these are not for serious carbines;).
I will however, keep the identity of the buyer secret so that don’t get dogpiled by the OEM nazis.
I also have 3 brand new Colt rifle buffer springs for use in my carbines that have VLTOR A5 receiver extensions, yes, I have non-OEM parts installed on some of my carbines (some are even Colts) but don’t tell anyone, I don’t want to get frog marched for having a non-OEM part on one of my guns:jester:. One of the springs is half an inch shorter than the other two. They are still in the sealed Brownell’s packages, so I can provide evidence in case someone calls me out.
IM or e-mail me if you want the springs.