Bullet weld and pressure relationship

[6Creed73]

I've read some stuff in the past about bullets cold welding to the case, I've also seen it called cold soldering. But I've never experienced it until today. I came across an old box of ammo that I loaded about 3 years ago and was pretty stoked because it's Peterson brass. So I decided to break them down to use the brass for some new loads.

I use a collet puller die and these things were an absolute bear to get apart, twice the bullet slipped out of the collet. I tightened the collet down like crazy and then thought I was going to rip my press off the bench or pull the case out of the shell holder before finally breaking it free. The amount of force it took to pull apart is nuts. You can see in the photo that the bullet has some kind of black corrosion or something. And it's important to note that these were found in a box from when I moved a few years ago and the box has been stored in a spare bedroom in the house which is climate controlled.

Anyway, this got me wondering about the pressure spike associated with shooting something like this, especially if the load is already on the high end of max. I was wondering if anyone has seen any studies or write ups about this, I looked but couldn't find anything. I imagine shooting a round like these would have to affect pressure in some way. At the very least, accuracy will be all over the place.

About two years ago I started putting neo lube #2 inside the necks prior to seating...not because I was worried about cold welding, but for more consistent seating. If I had the patience, I'd seat some dummies with neo lube and let them sit for an extended period and see if the bullets pull easily, I'm guessing they would.

 

[RegionRat]

Curious if you would be able to take a snapshot of the inside of that case neck?

 

[Straightshooter1]

I've read some stuff in the past about bullets cold welding to the case, I've also seen it called cold soldering. But I've never experienced it until today. I came across an old box of ammo that I loaded about 3 years ago and was pretty stoked because it's Peterson brass. So I decided to break them down to use the brass for some new loads.

I use a collet puller die and these things were an absolute bear to get apart, twice the bullet slipped out of the collet. I tightened the collet down like crazy and then thought I was going to rip my press off the bench or pull the case out off the shell holder before finally breaking it free. The amount of force it took to pull apart is nuts. You can see in the photo that the bullet has some kind of black corrosion or something. And it's important to note that these were found in a box from when I moved a few years ago and the box has been stored in a spare bedroom in the house which is climate controlled.

Anyway, this got me wondering about the pressure spike associated with shooting something like this, especially if the load is already on the high end of max. I was wondering if anyone has seen any studies or write ups about this, I looked but couldn't find anything. I imagine shooting a round like these would have to affect pressure in some way. At the very least, accuracy will be all over the place.

About two years ago I started putting neo lube #2 inside the necks prior to seating...not because I was worried about cold welding, but for more consistent seating. If I had the patience, I'd seat some dummies with neo lube and let them sit for an extended period and see if the bullets pull easily, I'm guessing they would.

View attachment 1499763

I use the Hornady bullet pulling collet die to pull bullets. If I suspect there is any of that cold welding, I'll just use a seater die to push down a little to break the weld and then the collet pulling die which then has no problem pulling the bullet. The bullets are then in much better shape for reuse.

 

[6Creed73]

Curious if you would be able to take a snapshot of the inside of that case neck?

I wish I did, they are currently in the tumbler.

 

[6Creed73]

I though about doing this because pulling them was getting tiring, but I was worried about messing up the seater die or stem. If I run accross this again, I'm going to try this.

 

[FrankG]

If a bullet is stuck like that in the case run it into a seater die first and seat the bullet down like .005” or so to break the seal first. Then it will be easier to pull.

I can’t give you a pressure spike number but I have seen bullets where they welded themselves to the case and upon firing there was so much pressure the gun to an extent blew up. No damage to the barrel or receiver but it blew the floor plate assy completely out the bottom of the rifle and cracked the stock.

 

[6Creed73]

If a bullet is stuck like that in the case run it into a seater die first and seat the bullet down like .005” or so to break the seal first. Then it will be easier to pull.

I can’t give you a pressure spike number but I have seen bullets where they welded themselves to the case and upon firing there was so much pressure the gun to an extent blew up. No damage to the barrel or receiver but it blew the floor plate assy completely out the bottom of the rifle and cracked the stock.

I'm glad I decided to break these down rather than shoot them.

 

[FrankG]

Watch your loading. Sometimes if the bullets are damp or the case for some reason… that will cause the bullets and case to weld together.

Not sure but a powder issue can cause it as well. I can post some pic’s tomorrow of that if I remember.

 

[K22]

I can’t give you a pressure spike number but I have seen bullets where they welded themselves to the case and upon firing there was so much pressure the gun to an extent blew up.

I am not disputing your observation, on the contrary, your observation has gotten my attention since I consider safety the number one consideration in reloading. Accordingly, I employ several "fail safe" procedures and make a serious effort to produce safe reloads. You might characterize my reloading approach as "risk adversed".

However, I have never paid attention to the "bullet weld" issue since I have never experienced any adverse effects of reloads that have carried over to the next season or a bit longer thus sometimes sitting for 12 to 18 months. Also, I never heard of this issue before I started going on the net. None of the reloading manuals and literature that I have mention it. I am not saying that this means that it doesn't occur.

Also, what I can't understand is why this condition does not apparently occur with factory ammo that may have been sitting on the shelves for years. Do you have any information on how they prevent this bullet weld issue, at least to the extent that it's not dangerous from over pressure.

 

[6Creed73]

Also, what I can't understand is why this condition does not apparently occur with factory ammo that may have been sitting on the shelves for years. Do you have any information on how they prevent this bullet weld issue, at least to the extent that it's not dangerous from over pressure.

I was wondering about this myself. Up until I struggled breaking these down today, I never gave cold welding a second thought. But it's now obvious to me that it can and does happen. What I'm still unsure about is if I decided to shoot these instead of breaking them down, would I even have noticed an issue.

But given how much force it took to pull the bullets, I can't believe there isn't some kind of pressure spike, even if it's a somewhat small spike.

I barely remember reading something about the Army testing the cold welding phenomenon and confirmed it does happen but determined that it caused no negative affects. This was years ago that I read it and unfortunately I can't find it, nor can I remember where I read it.

 

[Coyotefurharvester]

The Army wouldn't be concerned unless the rounds, didn't fire or damaged the firearm. Battle fired brass is not collected. And I doubt even 1 projectile in a 10000 actually hits enemy combatant.

 

[6Creed73]

The Army wouldn't be concerned unless the rounds, didn't fire or damaged the firearm. Battle fired brass is not collected. And I doubt even 1 projectile in a 10000 actually hits enemy combatant.

Agreed, if I remember correctly they wanted to see if it damaged firearms. Really wish I could find it...if I do I'll post it.

I was an armorer in the USAF and we had ammo that sat in the armory for years, in less than desirable conditions. Never heard of there being an issue.

 

[jackieschmidt]

After looking at that bullet, what is the difference between “cold welding” and corrosion?

 

[6Creed73]

After looking at that bullet, what is the difference between “cold welding” and corrosion?

I've always assumed "cold welding" was a made up term to reference corrosion.

 

[Straightshooter1]

After looking at that bullet, what is the difference between “cold welding” and corrosion?

As simple as I can put it: Cold welding has to do with how two metals react and bond together. Corrosion is an oxidation process, like when moisture gets involved.

 

[K22]

I was wondering about this myself. Up until I struggled breaking these down today, I never gave cold welding a second thought. But it's now obvious to me that it can and does happen. What I'm still unsure about is if I decided to shoot these instead of breaking them down, would I even have noticed an issue.

But given how much force it took to pull the bullets, I can't believe there isn't some kind of pressure spike, even if it's a somewhat small spike.

I barely remember reading something about the Army testing the cold welding phenomenon and confirmed it does happen but determined that it caused no negative affects. This was years ago that I read it and unfortunately I can't find it, nor can I remember where I read it.

Always err on the side of safety is my thoughts, it's ain't worth losing an eyeball.

What puzzles me is back in the 80's I had a friend who was into military firearms big time. He shot a lot of Army surplus 30 06 in the M1, 30 carbines, and 45 ACP's ammo from WWII and the Korea war and never had a problem with either pressure or misfires.

Maybe a simple solution to advance preloading and avoiding this issue is just to seat the bullets out a about .050" then reseat before using them.

 

[Outwest]

Is it possible for a few flakes of powder to be caught between the neck and the bullet causeing this problem?
I was loading some 300wsm the other day with H. Superformance and quite a bit of this fine powder was sticking to the inside of the necks. I was using a boat tail bullet.

 

[DiRTY DOG]

The mysterious cold weld problem that doesn't happen with factory ammo.

Maybe it's just your fingerprints on the bullets causing corrosion. Some people have very acidic fingerprints... Do you load with bare hands?

I wear nitrile gloves while reloading, always have. Curiously, I've never seen this "cold welding" phenomenon.

Some even brag about using a paper towel etc to wipe off sizing lube. How sure are those folks, that they aren't contaminating cases and bullets with lube/finger-sweat that could do weird stuff with time?

 

[jds holler]

I believe that it is caused by electrolysis between the two dissimilar metals. Even though brass and copper are kind of similar. (my theory and I'm sticking to it)

I do know that is a a real thing. I also never thought much about it until a while back I shot some 270 shells I loaded prolly 20 years ago. They shot horrible (about 3 MOA) and I decided to break them down and try some different things. A few shells in I was pretty amazed at the bond between bullet and neck. I had to bust them loose with my seater die, then pull. jd

 

[Olde Man]

A friend brought me a sporterized 22-250 Mauser the other day. He was having extraction problems. I had to help the extraction process with a cleaning rod. The ammo was factory Winchester. I had not previously looked at a mauser action so spent some time to undestand the extraction process. All said and done I had overlooked overpressure because it was factory Winchester. The primers were flattened and on a closer look the bullets had green corrosion at the bullet neck junction. I failed to remove the bullets with my impact hammer. It was a new one for me but at 76 years old there are a lot of new ones.