I was reading a thread on another site where the OP said he had loaded up a bunch of rounds of a specific load a couple years ago. It was a superbly accurate load at the time. Recently he tried shooting some of these loads and accuracy was poor. He put some of them in the press to try to seat the bullets a little deeper and he heard a distinct "pop" with each of them. He said they cold welded. My question is is this common and if so how do you prevent it? Is the answer to only load as much as you need at one time?

Load clean and "keep your ammo dry" is probably good advice for this. (The funkiest stuff I've seen has involved ammo stored in high humidity conditions and especially when there was a 'water soluble' lube involved. (Stuff like Lee Case Lube can act hygroscopic in humid conditions and get pretty gnarly, even when you think it has been wiped off quite well.)

I used to see it on my older reloads using rcbs case lube until I started doing a really good job of cleaning it out of the neck before loading.
Pretty ez to check your ammo...just try seating them deeper. Mine would really resist...then all of a sudden crack loose...and i could easily hear the "popping" sound.

moosemike, I would say the poster from another site has it right. Although I do not believe it has anything to do with lube. I have posted this before but will repeat. A friend who was an engineer, related to me that loaded cartridges will almost never deliver the accuracy of freshly loaded ammo. The metals react to each other, plus the brass will have different neck thickness. So,there will be plenty of variations between rounds because of neck tension and the welding of the metals.

My most common practice is to prepare cases for loading and then complete the loading when going out to shoot.

Please... explain to me how the two objects blend themselves into one?

The process isn't actually welding. Rather there may be some electrolysis taking places between dissimilar metals, in this case brass alloys which aren't exactly the same, perhaps even bronze sometimes. Moisture and other substances can also promote the process. So what causes the added 'pull' is actually a form of corrosion.

They're so close to each other on the nobility chart...

Maybe the tin in the brass is the issue?

You'll be hard pressed to find a match shooter who doesn't reseat his ammo just before a big match. They will load lots of ammo but leave it long, then before the match they reseat to break the cold weld.

Dick

All the shooters at the Bench Rest Shoots we hold at our range load just minutes before they shoot.
Very anal crowd.

Nonsense

How so? Please tell.

Got to agree with you. Out of the 18 competitors who shoot in the matches I run two reload during the match.

For those of you who have subscribed to Precision Shooting for a while, Randolph Constantine wrote an article in the 1990's about his experiences with "cold welding". It was entitled something like "Cold Welding Can Ruin Your Day". Constantine is/was a highpower competitor and also a rocket scientist who observed older handloads with drastic elevation problems. He sought the source of the problem and diagnosed the cold welding phenomenon.

What kind of matches or disipline, AJ? I have been doing the BBQ's for our club the last four years. 20-30+ competitors all sit at loading benches between legs and load the same 15-20 rounds all weekend.


P.S. CBRSA, Visalia Sportsmens Association/Dale Wimp rifle range.
Walt Berger is great to talk to, you just have to YELL.

It could be the zinc/copper in brass; tin/copper in bronze....in general, and who knows just exactly what in some of the alloys. But even different percentages of the same metals in two different contacting alloys could react I suppose.

I believe that this is a little recognized "secret". I have experienced it many times when pulling bullets from rounds that are at least several months old. It not only happens with modern smokeless ammo with conventional jacketed bullets, but also with black powder and lubricated lead bullets. In the latter case, I have done some experimenting and believe that it relates to the lube. It turns the insides of the case necks green, especially adjacent to the lube grooves. In extreme cases it feels like the bullet was glued in, requiring considerable force to pull the bullet. Some lubes seem worse than others.

As with most such things, there are experienced shooters who claim it doesn't or can't happen. My experience tells me otherwise.

Paul

I've been into benchrest shooting for a few years now, and it is very, very meticulous. I loaded good ammunition for 20+ years before I realized there were about 100 things I could have improved on. There are two schools of thought for loading for benchrest. One is to find a load your rifle likes, make a bunch of ammo and head to a shoot. Some people will have a barrel tuner and adjust it to make the most of shooting in the current conditions. The other thing to do is to get to the shoot and load for the conditions. If you keep log books, you'll find your favorite load will vary with the temperature and the wind. It's nuts, but matches are won and lost by thousandths of an inch. I'm not that nuts yet! I do buy hand made bullets though. It's a start.

By the way, I've never seen anyone re-seat bullets. My benchrest rounds don't have a lot of neck tension. I can push the bullets in against the table. No problem. I'm single loading though and I don't have to worry about recoil seating my bullets deeper in the magazine.

Centerfire Benchrest, 100 yard group and score matches. Our matches are only a one day event. The majority of shooters will tell you it isn't worth the hassle to bring their trailers and reloading equipment for a single day shoot. Group matches are won with teen aggs, score matches will take a 250-23X. Harrison is a tough place to shoot....

So the concensus is that this does happen and it's best to use "fresh" handloads. That makes me rethink my habit of loading a bunch all at the same time and keeping the loads around for a couple years until they're all shot off.

As far as your OP is concerned, I've done test by changing seating depth. I'll seat all the bullets long and when finished gone back and reset the seating die to seat bullets deeper. They all pop. I'm running .002" neck tension, you've got to break the neck tension which is gripping the bullet in order for the bullet to move. IMHO the seating pressure will be different than it was when originally seating the bullet.

While all this is very intersting regarding maintaining accuracy and all, I hve seem some worse cases senarios where cold welding really caused a problem.

Last year my brother in law gave me some 270 Winchester ammo since he had sold that rifle. He said he wanted me to pull the bullets. All this was ammo that either myself or another friend of his had loaded around 1978. He said he did not want someone else shooting it.

So, in my spare time I began pulling bullets using my RCBS kinetic bullet puller. It seemed to take a lot of pounding to get the bullets to come free. Finally, I pulled a bullet only to retrieve it from the bullet puller with the cases neck firmly attatched to it. Rather than pull the bullet, the bullet puller had simply pulled the neck off the case. Now that seems like an extreme cases of cold neck welding.

I am just going to throw all that brass away, I do not think it s safe to reload.

Here is a simple tip for those that haven't run into this problem before:

When you need to break down ammo, even fairly recently loaded rounds, first run them all through a seating die and push the bullets down into the case just a tiny bit further. This will free the bullet and make extraction of the bullet much easier.

This is especially true of very old ammo when using the kinetic (hammer) bullet pullers. (smack, smack smACK, SMACK SMACK!!...).

I recommend the Hornady collet bullet puller over the kinetic pullers.

+1000

would you say then, that the same would hold for factory ammunition?