The powders are made from many chemicals mixed together, .... Those trapped chemicals, over time will continue leach out of the powder. Some of them can and will attack metals.
"bullet weld" is not a new topic, not at all. IMO there are people who deal with complication, preferring to live in the real world, and those who selectively ignore stuff, because it overloads their apparatus. No one makes anyone read or discuss any of this. There is even room in the world for guys who make YouTube videos telling shooters to turn their FL dies down until they touch the shell holder, back down the ram and then turn another eighth to quarter turn. Imagine that.The internet has created all kinds of mystical phenomena in the shooting sports and has turned something that is relatively simple into something complex with dire consequences if you do not adhere to some prescribed theory. The two "biggies" are cleaning and barrel break in. Now enter a new one, "bullet weld".
In my early days it was "neck sizing". The claim was longer case life and better accuracy. This at least had some slight basis in true because we all were FL sizing cases incorrectly, blindly turning the FL die down per mfg.'s instructions, oversizing case. Once we learned how to properly FL cases, meaning adjusting the FL die to give optimum sizing by using either the rifle chamber or later bump cases to adjust the FL die, the myth was dispelled plus properly FL sized cases provide enhanced functionality.
I feel bad for new shooters entering the sport, it has to be so frustrating and confusing. I really believe all this BS is sucking the joy out of the sport creating neurotic shooters.
No, cold welding, as it has been termed happens. I'm done guessing why or what for but it happens. Along with not guessing as to why, it's likely under certain circumstances it happens sooner, later, or at all. But I've seen it with my own eyes and it's unmistakable. I'll leave the chemistry to the chemists but it definitely happens under the right circumstances. No doubt about that. It's just a fact, for whatever reason. Not picking on you but just because someone hasn't seen something themselves doesn't mean they are lying, mistaken or wrong.The thing called cold-weld is the observed propensity for a brass case and a copper bullet to stick together when pressed.
Metallurgically, there is no such thing. You can take a piece of brass and a piece of copper and clamp them together, and no matter how long you wait, they will not stick together.
In the context of a loaded round, there is more going on that might affect the outcome, such as any substance that may arise inside the case due to the degradation of the powder, and it seeps between the case and the bullet, reacting with the metals and acting like a glue. Some old ammo has a green stain where the bullet meets the case mouth, as if some liquid seeped out from inside and dried there.
That is a bonding caused by chemicals, which is not a cold weld. And that is what I've encountered pulling old ammo.
With clean surfaces, the force to pull a bullet is higher than the force to seat the bullet, and that has to do with the energy required to keep two surfaces sliding against each other, compared to the energy to get them to begin sliding.
Maybe that is what the 'cold weld' is referring to, that difference in force ?
I agree. I have experienced the "click" on reloads and do not deny that some kind of change has occurred. I just haven't detected any adverse effects on performance. It's the performance aspect where I there may be the possibility of speculation.To be clear, in the past I have attempted to disassemble ammo by using a inertial bullet puller, after which I decided to seat the bullets deeper. When I did that it took a LOT of effort on the press handle and when the bullets moved there was a loud POP, much louder than you heard in Cortina's video, earlier in this thread. After the bullets were reseated, I was able to remove them using my inertial puller. This is not conjecture or speculation, it is actual experience. Just because you have not experienced something does not mean that it is not happening.
I think I live in the real world, although with everything that's going on in this world today, I sometimes wonder."bullet weld" is not a new topic, not at all. IMO there are people who deal with complication, preferring to live in the real world, and those who selectively ignore stuff, because it overloads their apparatus. No one makes anyone read or discuss any of this. There is even room in the world for guys who make YouTube videos telling shooters to turn their FL dies down until they touch the shell holder, back down the ram and then turn another eighth to quarter turn. Imagine that.
I agree. I have experienced the "click" on reloads and do not deny that some kind of change has occurred. I just haven't detected any adverse effects on performance. It's the performance aspect where I there may be the possibility of speculation.
If I see statistically significant test data that substantiates a performance effect, then I'll shut up. Just because so and so match competitor does something doesn't substantiate a performance effect.
I think so but was there a performance effect? Is there a cause-and-effect relationship between the "pop" as you call it and results on target. If so, I am all ears. Explain what you observed regarding results on target from reloads with "bullet weld" versus those with no bullet weld. By the way, how do you know which rounds have bullet weld and those that don't unless you seat them just before you shoot them? How long does it take for bullet weld to show - which I believe was the OP's original question.After changing barrels I needed to reseat a batch of old loads and 75% of them popped with considerably higher force, is that statistically significant?
I think so but was there a performance effect? Is there a cause-and-effect relationship between the "pop" as you call it and results on target. If so, I am all ears. Explain what you observed regarding results on target from reloads with "bullet weld" versus those with no bullet weld. By the way, how do you know which rounds have bullet weld and those that don't unless you seat them just before you shoot them? How long does it take for bullet weld to show - which I believe was the OP's original question.
I keep making the same point over and over again, I am NOT challenging the "pop". I verified that too when I tested the premise on some round sitting for almost year. But I saw no effect on target of the other rounds in that batch. Year after year for more years than I can remember, I have had reloads carry over from season to season and they shoot the same as the previous year. That's all I am saying.
What I am seeking is some evidence that there is a performance effect.
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To me there are too many unknowns about the degree of cold welding to consider even trying to test for effects. If I plan to put up loads for a year using bullets (Hornady) which caused a problem, I will simply seat them long and do final seating just before shooting. Five minutes for peace of mind if nothing else.
I test ideas to see if they matter to me in my personal situation. If they don't I move on. If they do then I make adjustments to my process.Without discussion along with trial and error, how do we evolve ? Why is everything we haven’t personally experienced bullshit ?
I would imagine that you are familiar with seating force gauges. There is the K&M, The 21st Century, and most recently the AMP. Shooters use these to sort out loads based on relatively small differences in force required to seat their bullets. They do this because they believe, or have observed that these differences effect accuracy. Why don't you ask any competitive shooter whether he thinks that say 100 pounds or more difference in seating force would affect accuracy?I think so but was there a performance effect? Is there a cause-and-effect relationship between the "pop" as you call it and results on target. If so, I am all ears. Explain what you observed regarding results on target from reloads with "bullet weld" versus those with no bullet weld. By the way, how do you know which rounds have bullet weld and those that don't unless you seat them just before you shoot them? How long does it take for bullet weld to show - which I believe was the OP's original question.
I keep making the same point over and over again, I am NOT challenging the "pop". I verified that too when I tested the premise on some round sitting for almost year. But I saw no effect on target of the other rounds in that batch. Year after year for more years than I can remember, I have had reloads carry over from season to season and they shoot the same as the previous year. That's all I am saying.
What I am seeking is some evidence that there is a performance effect.
So, what have we concluded?I would imagine that you are familiar with seating force gauges. There is the K&M, The 21st Century, and most recently the AMP. Shooters use these to sort out loads based on relatively small differences in force required to seat their bullets. They do this because they believe, or have observed that these differences effect accuracy. Why don't you ask any competitive shooter whether he thinks that say 100 pounds or more difference in seating force would affect accuracy?
The problem here is that we have no way to identify which rounds are cold welded and which are not. That is the crux of the problem insofar as testing is concerned. I can tell you one thing that most who have experienced this would agree with. When we have gone through a set of ammo, after finding one that was cold welded, not all were, and there was no visual way to tell them apart.
When I want to know something I go out and do some testing, targets don’t spread conjecture.
