Derrek,Your grandfather told you and mine told me..."Don't chamber a round in your rifle or shotgun unless you are ready to shoot".That advice was good 65 years ago and it still applies today.Having said that your rifle fires using a spring as do any other powder burner rifles you may own.If you are on stand and feel sure a squirrel will make itself known sometime while you are sitting there, go ahead and chamber a round. You can rest assured the rifle will fire when you squeeze the trigger.If you need to change positions, get up and stretch, remember that rifle is loaded.I would unload it before moving around.That is just me.Stay safe and free.
If you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.
Quote from: Vee3 on September 16, 2017, 11:07:26 PMIf you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.Can you please explain this using different words? thanks.
Quote from: soloing2015 on September 25, 2017, 05:46:23 AMQuote from: Vee3 on September 16, 2017, 11:07:26 PMIf you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.Can you please explain this using different words? thanks.The hammer (or striker) spring in an airgun does not lose its strength by leaving the bolt cocked. It will only lose strength/wear out by cocking & firing the gun many thousands of times. Leaving it cocked for years will not change the spring's ability to fire the gun.It seems like a spring would wear out by keeping it compressed for a long time but it's not true. Take a car for example. There are hundreds of springs that have to stay compressed most of the time, usually never needing to be replaced over the life of the vehicle.That said, there are things that can cause springs to fail before they normally would. Stretching or compressing a spring more than it's designed to be is not good for them. Rust and certain chemicals (like acids) can weaken them.Unfortunately, there are even gun part manufacturers that write absolute nonsense about springs wearing out... "A firing pin striker spring will exhibit up to a 30% loss of power eighteen months after installation without even being used."https://www.jnpgunsprings.com/facts.php
Quote from: soloing2015 on September 25, 2017, 05:46:23 AMQuote from: Vee3 on September 16, 2017, 11:07:26 PMIf you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.Can you please explain this using different words? thanks.Thanks for your input. After doing some more research on the internet, it seems like this is not about the spring, rather than the design of the gun. Springs to get "weaker" when compressed past their yield. BUT, we do not know if the hammer spring in my Bobcat MK2 gets compressed past its yield or not. At least that is what I took from reading this: Was going to just post the link, but it says that I am not allowed to??? hey!? Anyhow, here it is:Quote:Ramanath Iyer, studied at University of SouthamptonYour dad was right about physics, but wrong about your toy. There are some criteria for the spring to lose its action. The actual reason for it is given at the end of answer, but let's start with basics.The behaviour of spring is the same as that of any other object. Any object when subjected to stresses tries to either resist or deform depending on the capacity of the object to do so. A rubber band when stretched deforms easily, but when released returns back to its original shape (same behaviour as a spring). When the stretching force is applied it deforms but at the same time, the energy is stored within the material and that energy is used to bring it back to its original shape. When that happens the object is said to be elastic. A plastic material, on the other hand, deforms permanently which means the energy is not stored, rather spent on rearranging the material's internal crystal structure. Such behaviour is also exhibited by metals. Lets consider steel here. Even steel behaves likes an elastic object when forces within a certain limit are applied. (Having said that all materials have that limit). It is called the yielding point. (or yielding strength, File:Stress Strain Ductile Material.png). When material is subjected to stress above its yield strength the material deforms (changes original shape) permanently or breaks, be it rubber or steel. But there are other mechanisms in which a material can deform. One is through fatigue, in which repetitive stresses are applied to the object for a number of times after which it fails. Higher the number of cycles, lower the stress required to deform. (But then the stress has to be above a specific minimum value for fatigue failure to occur.) Aircraft wings and turbine blades are subjected to cyclic stresses continuously during flight, and there has been several disastrous failures because of fatigue failure.Another mechanism is Creep (deformation). This is perhaps what your father had in mind. A material, when subjected to a load (even below yield strength) for extended periods of time deforms under that load. Here, in this case, the spring left loaded for years could have deformed permanently and may not have launched the projectile, had the temperature in which your toy has been kept all these years were sufficiently high. But in your case neither the temperature or the compressive force was high enough to induce creep. One of the most recent and tragic examples of creep failure is the World Trade Center collapse.Edit: World Trade Center collapse.The twin towers of WTC 1 & 2 had 110 floors. The aircraft impacted 93-99th floors and 77-85th floors of Towers 1 & 2 respectively. The designers of the towers had considered aircraft impact on towers while designing the structure and according to their analysis the towers were to sustain impacts up to a 600miles per hour collision by a Boeing 707. The actual impacts on 9/11 were at lower flight speeds but larger aircrafts. Though the designers did a brief analysis of the flight fuel being dumped on the building and the resultant fire, they didn't not have the know how or resources to accurately model creeping of structure. Because the aircraft impacted up to 30 floor below the top of tower, and spilled substantial fuel which ignited and resulted in temperatures close to 800C on the exposed structure, it was not able to withstand the weight of those 30 floors on top of it. (Creep is more pronounced at very high temperatures close to melting point of metal) So the floors that met with collision collapsed which resulted in the top floors coming down with high kinetic energy. The momentum of the collapsing top floors were too high for the floors below to withstand and it cascaded.End Quote.Quote:Alan C Reynolds, BSc Honours in Mechanical Mechanical Engineering, Trent Polytechnic (1978)This is an old question with a new life. The older answers are awesome.Spring take in what is called permanent set. This is when a spring is compressed and held in that position for a long time. If this does happen it is often because of poor design.In a compressed spring the stresses are complex because of a combination of bending and torsion. These combined loads should not exceed the matrerial yield. Indeed, most would design to less than 50% of yield. (This is not always possible. )If taken past yield the spring will lose some stored energy equivalent to the reading stress. So it will not all of its spring.Another consideration is temperature. This is often overlooked in any spring design. Mechanical properties of materials can vary significantly with temperature.Finally, for certain materials you will get a form of creep. This is more likely in thermoplastic materials than metals but not exclusive. Again if this occurs it is due to poor spring design.I hope this helps.Alan.End Quote.thanks...The hammer (or striker) spring in an airgun does not lose its strength by leaving the bolt cocked. It will only lose strength/wear out by cocking & firing the gun many thousands of times. Leaving it cocked for years will not change the spring's ability to fire the gun.It seems like a spring would wear out by keeping it compressed for a long time but it's not true. Take a car for example. There are hundreds of springs that have to stay compressed most of the time, usually never needing to be replaced over the life of the vehicle.That said, there are things that can cause springs to fail before they normally would. Stretching or compressing a spring more than it's designed to be is not good for them. Rust and certain chemicals (like acids) can weaken them.Unfortunately, there are even gun part manufacturers that write absolute nonsense about springs wearing out... "A firing pin striker spring will exhibit up to a 30% loss of power eighteen months after installation without even being used."
Quote from: Vee3 on September 25, 2017, 12:23:55 PMQuote from: soloing2015 on September 25, 2017, 05:46:23 AMQuote from: Vee3 on September 16, 2017, 11:07:26 PMIf you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.Can you please explain this using different words? thanks.The hammer (or striker) spring in an airgun does not lose its strength by leaving the bolt cocked. It will only lose strength/wear out by cocking & firing the gun many thousands of times. Leaving it cocked for years will not change the spring's ability to fire the gun.It seems like a spring would wear out by keeping it compressed for a long time but it's not true. Take a car for example. There are hundreds of springs that have to stay compressed most of the time, usually never needing to be replaced over the life of the vehicle.That said, there are things that can cause springs to fail before they normally would. Stretching or compressing a spring more than it's designed to be is not good for them. Rust and certain chemicals (like acids) can weaken them.Unfortunately, there are even gun part manufacturers that write absolute nonsense about springs wearing out... "A firing pin striker spring will exhibit up to a 30% loss of power eighteen months after installation without even being used."in other words, keeping the gun cocked will NOT wear out the gun and it will NOT harm the gun in anyway.
Quote from: soloing2015 on September 25, 2017, 05:46:23 AMQuote from: Vee3 on September 16, 2017, 11:07:26 PMIf you're talking about the spring's safety, as in "taking a set," you can leave it cocked forever with no damage. Coiled wire compression springs wear out from from the Compression/extension cycle, and any set they take happened on the 1st compression.Can you please explain this using different words? thanks.The hammer (or striker) spring in an airgun does not lose its strength by leaving the bolt cocked. It will only lose strength/wear out by cocking & firing the gun many thousands of times. Leaving it cocked for years will not change the spring's ability to fire the gun.It seems like a spring would wear out by keeping it compressed for a long time but it's not true. Take a car for example. There are hundreds of springs that have to stay compressed most of the time, usually never needing to be replaced over the life of the vehicle.That said, there are things that can cause springs to fail before they normally would. Stretching or compressing a spring more than it's designed to be is not good for them. Rust and certain chemicals (like acids) can weaken them.Unfortunately, there are even gun part manufacturers that write absolute nonsense about springs wearing out... "A firing pin striker spring will exhibit up to a 30% loss of power eighteen months after installation without even being used."
i'm always cocked when hunting no matter what type of propellant......
I only leave my gun cocked when I am in hunting mod and prepared to shoot. All other times it is uncocked with an empty bore. It is the safest practice for me and the others around me.No, I am not concerned about wearing out the hammer spring. I have notice a weakening of some springs after I put them in a fully bound position. They are never as strong again. My experiences with springs do align with Vee3's input.
Quote from: gendoc on September 25, 2017, 07:05:16 PMi'm always cocked when hunting no matter what type of propellant...... Do I really want to hear about that?! : )
Quote from: soloing2015 on September 25, 2017, 08:59:59 PMQuote from: gendoc on September 25, 2017, 07:05:16 PMi'm always cocked when hunting no matter what type of propellant...... Do I really want to hear about that?! : )no "pun" intended in my statement. i thought about maybe someone would question... but i kinda forgot about it as its justa truthful harmless comment....