Home Forums Hunting & Shooting Ask The Gunwriters Cold Weld question?

I feel more guys view this forum than others is why its not in Reloading. I have experienced "cold weld" on years old handloads. I never sweated it, but got to wondering. I use Imperial Sizing Wax and every now and then will swab the inside on the necks for easier upstroke to lessen case stretch. It is non contaminating. To load up some ammo for storage, should I a. swab every inside case neck when seating a bullet or b. swab the inside case neck after sizing and let dry then seat a bullet? I'm not worried about waterproofing, etc. Thanks

or (c) worry about it on the "back end" - e.g. seat the bullet a little long before storage and break the weld by seating to desired COAL when ready to go shoot it.

FWIW "cold welding" is a diffusion process, requiring two surfaces of similar composition (eg cartridge brass case and gilding metal jacket) to be in intimate contact. Time and temperature are also factors. It is based on atoms from the participants wandering around, and crossing the interface. Enough of them do it and the interface gets "blurred", forming a bond. If there's something between the surfaces, like wax, it impedes or prevents this wandering across the interface.

As long as the wax is there after the bullet is seated, I can't immediately see why it makes a difference whether you let it "dry" before seating or not. There again I don't use that particular product. Is it just a loss of solvent that you are asking about?

It seems like I get more cold weld issues if I size, tumble, clean necks and load in quick succession.
If I size, tumble, don’t clean the necks with a brush, and let the necks cure for several weeks, I get less cold weld problems.

It doesn't matter much what it is that lies between the bullet and the case, as long as it is something that keeps the atoms from freely crossing the interface. In your particular case it may well be a bit of dust and a bit of tarnish.

Personally I don't clean inside the case necks, and the carbon residue from firing seems to do the job. FWIW I don't tumble brass either, as I see no benefit to it, and patina is slightly protective. I save what to me is a completely unnecessary bit of work too.

Yep! (As we have discussed more on than once here over the years...._

Thanks. I've done the "break the seal to COL later" before. I never considered not cleaning the inside of the case neck before! I always have run a brush in there, ha. I guess I was afraid of the grit scarring my sizing die? Anyhow, great ideas guys, thanks again.

I tumble till it's nice and polished. I leave the necks alone. After tumbling, it still has enough carbon, or debris, that cold weld is never an issue.

Leaving the powder residue on the inside of the necks is the best way to get ahead of any issues. A quick pass with a synthetic brush is all that's needed, at most. The powder residue is also an excellent coating when seating bullets.

On new brass, I chuck a snug fitting bronze bore brush in a cordless drill and make a few up and down passes in the necks....really helps condition the necks prior to being fired the first time. Think of it as a light burnishing. On turned necks, it's not needed as they get conditioned by rotating on the turner mandrel.

Good shootin' -Al

Yep I never clean the inside of my case necks. I tumble only and go from there. Never had a cold weld issue on used brass ever if I leave the inside of the neck just a bit "dirty"

I’ve had this problem, but only when I used to wet clean. Tumbling, no issues.

[question not directed specifically to you SDHNTR]. How does this "problem" typically manifest itself? I don't load ammo for long-term storage, I like fresh stuff.

Muskeg- I had some leftover 35 Whelen Ackley Improved from a first trip t0 South Africa. Fireformed new brass, loaded to 2600 with Barnes 250X with 2015br. 10 yrs later I shot some over the chrono and got 2640+. I cracked the weld by seating a smidge deeper, back to 2550-2600. No biggy. Just wondering.

I bought a bottle of Neolube No.2 for experimentation purposes. I want to see if using it to coat the inside of the case necks of brass freshly tumbled in wet media is effective in preventing cold weld, but I haven't begun to fiddle with it yet. Maybe it'll work, maybe it won't. If not, then it may be useful for other prurposes.

How do you tell if cold weld has occurred with your reloads?

Set it in a seating die adjusted slightly deeper than original Oal and gradually put pressure on it
You will either get a strong resistance before it breaks or a snapping sound maybe both
It can cause pressure spikes , I don’t think the spike will be enough to worry about I’m no expert by any means either
Another sign is if it’s a load that shot tight and you start getting flyers
Kenneth