No Cold Welding

I partially pulled 50 .308 bullets that I have had loaded for at least 2 years. No sign of cold welding. All broke loose smoothly with the same amount of force as far as I could tell. I pulled a couple, re-coated them, seated and then removed them again. The force felt the same as the 2 year old loads. These were all Hornady .308 / 208 grain EDL Match bullets in new Hornady cases, .002" interference fit, and I coated them all with Imperial Dry Lube graphite powder. I also spot checked about 20 Hornady .308 / 168 grain bullets in Lapua cases that have been fired a couple times. They all released easily too and had been loaded over 2 years ago too. I've had a few rounds in the past that took quite a bit of force to get them to break loose that weren't coated but were in fired cases with some carbon left in the necks. Not all the ones in a batch but probably 1 out of every 10. Never would have known until I pulled them to change the powder loads. I noticed I had a few that showed slight pressure signs (ejector marks) even though everything else was the same and down to within .02 grain of powder and seated to within .001".

 

This is a controversial issue - there are many "opinions" on it. I'll weigh in on my experience which I do not claim is conclusive or am I an expert on this subject - just an "expert" on hunting groundhogs.

First, my perspective is from a precision varmint / predator hunting purpose where my accuracy standards are modest compared to a bench rest competitor. If I'm in the + / - 1/2 moa range group wise this meets my requirements for a varmint / predator load.

Second, I often use the winter months to load up several hundred rounds for about 10 varmint rifles for practice sessions and varmint hunting in the spring and summer. Also, I sometimes have loaded rounds remaining after varmint / predator seasons which carry over to the following season.

Third, I have never detected any change in accuracy in these rounds that have sat unfired for several months even into the next season.

Fourth, I've seen some amazing groups shot at the range by others with premium factory ammo that was sitting on the dealers shelves over an indefinite time. Maybe those manufacturers have some special process they use to minimize "bullet weld" if there is such a thing, I don't know.

 

If you do some testing over a long period of time, like years, youll see that carbon left in the necks will weld the bullets in and when looked at under magnification they will be pitted, where a clean brass neck will not increase bullet break away force or “pop” when seated deeper. Of course im going to get flamed by theorists but this is what i see.

 

Cold welding, I have seen with some of my older handloaders. While I brush my necks, I do not completely remove the carbon. The ammo was roughly 10 years old. Cold welding and a worn barrel was my reason for pulling. Tried pulling the first one only distort the bullet. Seated them 0.02" deeper they pulled much easier. Got carried away and pulled most of my older handloads. Decided that 50 per rifle is enough.

 

Yes, it is called crimping.

 

Some time back I was given 20 boxes of loaded .264 Magnum rounds. Having no use for it I decided to pull the bullets and sell the cases. Well, according to the writing on the boxes they had been loaded in the late 60's. On a lot of the cases I ripped the neck off and the bullet never moved.

 

I did 800-900 reloaded ..223 my dad had bought in 1992... They had carbon in the necks from being previously fired and loaded... Some were normal , some fell out basically but some were stuck and I meen stuck... You could see were they had welded were the two metals touched even with the carbon... I didn't see any pitting but you could tell something was up.... No matter what you call it they were stuck together and pulled the metals apart...

 

Hmmmm. Uh, welded???.. Well, OK, if that's what you want to call it. My welding supply background wouldn't exactly call it welded, but I get the point, and if that works for the problem I'm OK with the description, accurate or not. No need to get anyone's pants in a knot.

 

But did any of the "cold welded" rounds produce erratic shots / groups, i.e. negative performance affects - not theoretical predictions but actual results on paper from shot fired?

 

I don't know how you could tell. They all don't stick. The only way to tell is to pull the bullets enough to break them loose and then they are no longer stuck at that time. I know one batch that had some cold-welded (that seems to be the term most people use), had random high pressure signs. The bullets and cases were all the same lot numbers and everything loaded exactly the same with only about .002" interference fit in the necks. Sticking that tight can't be a good thing.

A solution may be to load all your rounds but don't seat them all the way until the time when you want to use them. I'm leaving about 50 of the loaded rounds using the graphite lube for another year to see if there is any difference.

 

Wonder what would have happened if you tried to fire any of them? A few years ago I was wondering about lubing bullets while seating them. I tried some Hornady Unique. They felt nice and smooth seating and pulling them back out. Then I got the idea about heat. What if the round sat in a hot chamber? I used a torch and heated the necks on a few (no powder or primers of course) and not really that hot. The brass never changed color. Red Loctite couldn't have worked any better. They could not be pulled using an RCBS puller in the press. I did deform the shoulders on some trying. None broke loose.

 

The cold welding is really like electrolosis without the current. Its the dissimilar metals

 

A couple years ago I loaded 160gr Noslers in 7 Mag with 62gr H4831. Good accurate load, not max. 2-3 years later I got popped primers and significant ejector marks. Most of the rounds were fine but about 4 out of 10 showed these signs. Pulled the rest with great difficulty. Powder charge was correct. “Cold welding “ is the only thing I can think of that could explain this.

 

I have a 30-338 rem 700 that I have not used for 12 years, shoulder injury, got it out cleaned the barrel on the first shot I had to use a rawhide mallet to open the bolt, shot one more same thing, I use an inertia puller it took several hard hits to extract the bullet the powder charge was right on, now I know what had happened, weld bond. Thanks for the great information.

 

I am curious if there are environmental factors that drive this. High temperatures high humidity, salty coastal conditions. I'm sure there are some common factors in storage that make this more likely.

 

That's my line of thinking too and possibly perspiration on your hands. Funny that it is random. I just pulled 40 more rounds apart about 3 years old. All loaded at the same time with the same components. Most pulled out like they were just done today, 7-8 took noticeably more force to pull, and 1 wouldn't budge. I tightened the puller on as tight as I could and it slipped off twice as I slapped the handle with my hand pretty hard, scaring the bullet, then the 3rd time it came out. The bullet and case didn't show much if any pitting but it did shine or scuff the part of the bullet that was in the neck.

 

It wouldn't be surprising if environmental [storage] conditions might play a role in how fast the process occurs. It might depend on how tightly the bullet was seated in the neck (neck tension), as the humidity and/or salt would actually have to reach at least some distance down in between the case wall and bullet bearing surface to have a sizable effect. I'd also guess that the condition of the inside of the neck wall might also be a factor. In case necks that had a thin layer of some carbon, oxidation, or other "patina" on the inside surface, you might imagine that it would serve to inhibit the direct contact between the case brass and bullet jacket, thereby slowing down any reaction.

 

I don't what to believe any longer . Last year I took 3rd in a local competition,this year I took first ...using last years leftover loads. My score went up 3 points .

 

https://wiki2.org/en/Cold_welding

 

Because of the specialized conditions required to achieve it you won't ever see any "cold welding". What some people call cold welding is probably some sort of adhesion or cohesion. Just a case of semantics of course