I just spent some time putting together an FAQ on springs I thought would be helpful. Some of the stuff may be a bit controversial, but I am open to discussions.
Of Springs and Things:
Answering the Most Common FAQs about Gun Springs
Aside from ammunition the gun spring seems to be the most misunderstood common part associated with firearms. Internet forums are packed with threads about when to change them, and what can damage them. In the past I too have succumbed to the madness of the gun spring scouring forums for answers to my questions. As is sometimes the case I ended up with more questions than answers I was satisfied with. As with many things firearm, hearsay and legend often overshadow hard facts, and science. Then one day while reading through another forum thread full of conflicted answers it dawned on me…a gun spring is just a spring like any other. There is no mystery, no magic, and certainly no reason to be confused. Here are the most common questions I see on message board, and the answers to them.
Will leaving magazines loaded for extended periods of time cause the springs to weaken?
The honest answer is YES. There is no way around it. All loaded springs suffer “load loss” or “stress relaxation” when subjected to stress for any extended period of time. The degree of load loss depends on how heavily loaded the spring is, the type of material, the amount of time the load is applied, and the temperature. The degree of loading depends heavily on the design of the magazine itself, and how compressed the spring is. The quality of material is very important, and the higher the tensile strength of the wire the less it will be affected. ROTATING MAGAZINES DOES EXTEND MAGAZINE SPRING LIFE.
But I thought only cyclic loads damaged springs like loading, and unloading the magazine.
There are actually several ways for a spring to fail.
1. Mechanical overloading
2. Fatigue (fracture)
3. Stress relaxation (load loss)
Mechanical overloading is very uncommon in firearm springs simply because firearms have well defined ranges of motions that the designers have accounted for. If a spring is ever overloaded it may be shorter than before, and may be kinked. A spring in this condition needs to be replaced, but not before the firearm is inspected for proper functioning.
Fatigue failures of springs are caused by repeated cycling of the spring during normal operation. Fatigue failure in magazine springs is not an issue because of the number of cycles that would be required to initiate such a failure. Typically fatigue failures start at 10,000 cycles for some highly stressed springs, and may not be an issue for millions of cycles for lightly loaded springs. 10,000 cycles for a typical 10 round magazine would mean firing 100,000 rounds from the same magazine! Where we can see fatigue failures of springs in firearms is in small springs in the fire control mechanism. These springs may in fact see that many cycles considering the frequency of dry fire, and function checks performed by some users.
In the case of stress relaxation, or load loss we may not see anything at all. The spring may lose tension very slowly until it can no longer perform its job properly. The most common symptom of load loss in magazine springs would be double-feeds. If your pistol starts to double-feed try a different magazine. If needed replace the spring in the magazine, but be sure to inspect the magazine body, and feed lips for any cracking, or deformation. Recoil springs experience rapid compression, and may suffer additional effects from shock loading. Even a 10% load loss on a 16lb spring has reduced it to only a 14.4lb spring. Would you shoot .45 ACP “hardball” in a 1911 with a 14lb spring? Common symptoms of load loss in recoil springs are changes in ejection patterns. Specifically cases being thrown further, as well as a change in recoil feel.
But what about all those 1911 magazines left loaded since WWII that still worked fine?
When JMB designed the 1911 it had a 7 round magazine. It was intended to be carried loaded for extended periods of time during combat, and as such the spring was designed to have as little stress on it as possible. Some time later somebody had the idea to make room for an extra round by redesigning the spring, and follower. More stress was put on the spring, and problems began to occur. Some magazines seem to be very easy on springs, and some are pretty hard on them. As a general rule if it is easy to load the magazine to capacity then chances are that the stress on the magazine spring is fairly light. If you need to struggle to put the last round in the spring is being heavily worked as well. It may be a good idea to download one round in those cases especially if the magazine will be loaded for extended periods of time.
Hey I just bought a new recoil spring, and it got shorter, is it damaged?
No the spring is not damaged. In fact it is better than new. Your spring has now been “preset”, and will be able to handle greater load with a longer fatigue life. Manufactures intentionally design the spring to be longer than needed. Once the spring is put into operation it will take a permanent set after about 10 cycles. This set is actually plastic (permanent) deformation of the spring. This deformation sets up beneficial residual stresses in the spring that increase the load capacity, and fatigue resistance of the spring.
If a spring gets weak can’t I just stretch it out to give it more tension?
Yes you can, but it won’t last long. In the above case the spring was plastically (permanently) deformed in the direction of operation of the spring to set up beneficial stresses in the spring. Deforming the spring against the direction of operation has an opposite effect, and can lead to rapid loss of tension, and even spring failure.
Don’t Chrome-Silicon Springs solve all these problems?
No not really. Chrome-silicon springs are intended to operate in higher temperature ranges than music wire. As such they are more resistant to load loss at higher temperatures than music wire. However music wire typically has a higher tensile strength so at room temperature there may not be any benefit to Chrome-Silicon. However in some applications such as machinegun (automatic weapon) extractor/ejector springs. There may be some benefit to using Chrome-Silicon, or even high temperature stainless steel springs. In these cases there may be significant heat in the bolt area of the weapon which may cause conventional springs to fail more rapidly.
Disclaimer:
The author of this article is not affiliated with any spring manufacturer. The author is not responsible for any injuries, or damage that results from the use, or misuse of any information contained in the above article. Ensure you understand the proper methods for disassembling, and reassembling your firearm before changing any components. Always practice safe gun handling when performing any maintenance on a firearm.
Of Springs and Things:
Answering the Most Common FAQs about Gun Springs
Aside from ammunition the gun spring seems to be the most misunderstood common part associated with firearms. Internet forums are packed with threads about when to change them, and what can damage them. In the past I too have succumbed to the madness of the gun spring scouring forums for answers to my questions. As is sometimes the case I ended up with more questions than answers I was satisfied with. As with many things firearm, hearsay and legend often overshadow hard facts, and science. Then one day while reading through another forum thread full of conflicted answers it dawned on me…a gun spring is just a spring like any other. There is no mystery, no magic, and certainly no reason to be confused. Here are the most common questions I see on message board, and the answers to them.
Will leaving magazines loaded for extended periods of time cause the springs to weaken?
The honest answer is YES. There is no way around it. All loaded springs suffer “load loss” or “stress relaxation” when subjected to stress for any extended period of time. The degree of load loss depends on how heavily loaded the spring is, the type of material, the amount of time the load is applied, and the temperature. The degree of loading depends heavily on the design of the magazine itself, and how compressed the spring is. The quality of material is very important, and the higher the tensile strength of the wire the less it will be affected. ROTATING MAGAZINES DOES EXTEND MAGAZINE SPRING LIFE.
But I thought only cyclic loads damaged springs like loading, and unloading the magazine.
There are actually several ways for a spring to fail.
1. Mechanical overloading
2. Fatigue (fracture)
3. Stress relaxation (load loss)
Mechanical overloading is very uncommon in firearm springs simply because firearms have well defined ranges of motions that the designers have accounted for. If a spring is ever overloaded it may be shorter than before, and may be kinked. A spring in this condition needs to be replaced, but not before the firearm is inspected for proper functioning.
Fatigue failures of springs are caused by repeated cycling of the spring during normal operation. Fatigue failure in magazine springs is not an issue because of the number of cycles that would be required to initiate such a failure. Typically fatigue failures start at 10,000 cycles for some highly stressed springs, and may not be an issue for millions of cycles for lightly loaded springs. 10,000 cycles for a typical 10 round magazine would mean firing 100,000 rounds from the same magazine! Where we can see fatigue failures of springs in firearms is in small springs in the fire control mechanism. These springs may in fact see that many cycles considering the frequency of dry fire, and function checks performed by some users.
In the case of stress relaxation, or load loss we may not see anything at all. The spring may lose tension very slowly until it can no longer perform its job properly. The most common symptom of load loss in magazine springs would be double-feeds. If your pistol starts to double-feed try a different magazine. If needed replace the spring in the magazine, but be sure to inspect the magazine body, and feed lips for any cracking, or deformation. Recoil springs experience rapid compression, and may suffer additional effects from shock loading. Even a 10% load loss on a 16lb spring has reduced it to only a 14.4lb spring. Would you shoot .45 ACP “hardball” in a 1911 with a 14lb spring? Common symptoms of load loss in recoil springs are changes in ejection patterns. Specifically cases being thrown further, as well as a change in recoil feel.
But what about all those 1911 magazines left loaded since WWII that still worked fine?
When JMB designed the 1911 it had a 7 round magazine. It was intended to be carried loaded for extended periods of time during combat, and as such the spring was designed to have as little stress on it as possible. Some time later somebody had the idea to make room for an extra round by redesigning the spring, and follower. More stress was put on the spring, and problems began to occur. Some magazines seem to be very easy on springs, and some are pretty hard on them. As a general rule if it is easy to load the magazine to capacity then chances are that the stress on the magazine spring is fairly light. If you need to struggle to put the last round in the spring is being heavily worked as well. It may be a good idea to download one round in those cases especially if the magazine will be loaded for extended periods of time.
Hey I just bought a new recoil spring, and it got shorter, is it damaged?
No the spring is not damaged. In fact it is better than new. Your spring has now been “preset”, and will be able to handle greater load with a longer fatigue life. Manufactures intentionally design the spring to be longer than needed. Once the spring is put into operation it will take a permanent set after about 10 cycles. This set is actually plastic (permanent) deformation of the spring. This deformation sets up beneficial residual stresses in the spring that increase the load capacity, and fatigue resistance of the spring.
If a spring gets weak can’t I just stretch it out to give it more tension?
Yes you can, but it won’t last long. In the above case the spring was plastically (permanently) deformed in the direction of operation of the spring to set up beneficial stresses in the spring. Deforming the spring against the direction of operation has an opposite effect, and can lead to rapid loss of tension, and even spring failure.
Don’t Chrome-Silicon Springs solve all these problems?
No not really. Chrome-silicon springs are intended to operate in higher temperature ranges than music wire. As such they are more resistant to load loss at higher temperatures than music wire. However music wire typically has a higher tensile strength so at room temperature there may not be any benefit to Chrome-Silicon. However in some applications such as machinegun (automatic weapon) extractor/ejector springs. There may be some benefit to using Chrome-Silicon, or even high temperature stainless steel springs. In these cases there may be significant heat in the bolt area of the weapon which may cause conventional springs to fail more rapidly.
Disclaimer:
The author of this article is not affiliated with any spring manufacturer. The author is not responsible for any injuries, or damage that results from the use, or misuse of any information contained in the above article. Ensure you understand the proper methods for disassembling, and reassembling your firearm before changing any components. Always practice safe gun handling when performing any maintenance on a firearm.
