How long until cold welding occurs?

[Idaho-Lefty]

THIS ^^^ would Be, my Guess also !
Kinda was thinking,.. 3 years, 4 Month's, 7 Days, 45 minutes, tho ! ( Just, a Little,.. LONGER ! )

 

[10XSHOOTER]

If you look at Military loaded ammo from the 50's to 70's.
There is a black tar sealant on the bullets.
this was to prevent the Galvanic welding of the bullet to the case
Allows the ammo to be stored for Many years

 

[ShtrRdy]

Why does the shoulder part of that case not look like brass?

It's new brass that has an anneal color to the neck and shoulder.

 

[markm87]

If you look at Military loaded ammo from the 50's to 70's.
There is a black tar sealant on the bullets.
this was to prevent the Galvanic welding of the bullet to the case
Allows the ammo to be stored for Many years

This is still used on a lot of current ammo. Most of us assumed it was to keep the propellant dry if the round got wet.

I've only felt the crack when decapping brass that sat out in the elements for a long time and got wet. The primer cups sometimes seem to fuse to the pocket walls.

 

[fatelvis]

Since I LEAVE, a Little bit of, Carbon "Soot" and Plastic Brush, the Neck's insides with, Hornady's waxy Unique Lube,. THIS Cold weld, Chit, has NEVER Been, an "issue" for Me, since Boyhood, Mid 1960's,..
when, I started Reloading.
I've Had, NO issues with, 20 to, 30 Year Old,.. Hunting, Ammo.
I would NEVER, ever, "Deep Clean", a cartridge "Neck",.. Shtr Rdy,.. IS,.. Bang "On" !!!
How Long it Takes to, "Cold Weld" I have NO idea and DON'T care, as it's NEVER Been, an issue for, Me !

Thank you for your response. Let me ask… have you EVER loaded VIRGIN brass? I usually leave carbon in the neck also, but right now I am loading several hundred virgin cases, and the cold Weld situation has me concerned, if I don’t fire them for an extended period of time.

 

[Idaho-Lefty]

Thank you for your response. Let me ask… have you EVER loaded VIRGIN brass? I usually leave carbon in the neck also, but right now I am loading several hundred virgin cases, and the cold Weld situation has me concerned, if I don’t fire them for an extended period of time.

I use, a tiny Bit of Hornady Unique Lube on a Plastic Brush, ( 3-4 strokes, in each ) on Virgin Brass and I won't wait, 5 years to Shoot them, up ( just in Case ),.. LOL ! The Carbon "Soot" / Unique Lube, works,.. BEST !

 

[Fire Dog]

Why does the shoulder part of that case not look like brass?

Just discoloured due to annealing… You would see that effect on any factory ammo even the stuff that is factory polished on the outside if you opened one.

 

[c3d4b2]

I have seen cold welding performed to seal electronic cases.

This article does a decent job explaining the process.

Cold Welding: Welding in Space, Pros and Cons of Cold Welding

This article will discuss cold welding in space, cold weld aluminum and other metals, cold welding with TIG, and related topics.

workshopinsider.com

Here is a link that offers anouther possibility

How do metals in contact fuse together?

A threaded brass plug screwed into a threaded brass coupling will corrode and become fused together when subjected to warm humid air and undisturbed for a long period of time (10 or 20 years). Since corrosion removes metal, how is it that the plug cannot be removed after it apparently corrodes...

www.eng-tips.com

 

[ELR LVR]

Why does the shoulder part of that case not look like brass?

Heat Bluing from the annealing process

 

[Fire Dog]

Thank you for your response. Let me ask… have you EVER loaded VIRGIN brass? I usually leave carbon in the neck also, but right now I am loading several hundred virgin cases, and the cold Weld situation has me concerned, if I don’t fire them for an extended period of time.

Neolube #2 can be your friend… or just mix up some Micro-fine door lock graphite with a bit of Isopropyl alcohol {much cheaper} and apply a light coating to the inside of the case neck.. Easy on the mandreling and seating and I am guessing will never let a “weld” situation occur.
It is a dry lube {when the alcohol evaporates} unlike the suggested Hornaday Unique Lube or any other lube that is not a “dry” lube and you will find that though it may work, it will stick granules of powder to the case neck as you fill the case.
Yes, I have loaded lots of “Virgin” brass and never had a problem.

 

[Syncrowave]

Maybe it's better to think of it as a galvanic corrosion issue than a cold welding one?

That would be my guess...this site suggests that the gilding metal jacket (at 95% Cu / 5% Zn) would be the cathode and the brass case (30% Zn) the anode. But if it is galvanic corrosion, keeping the ammo absolutely dry should prevent it. Without an electrolyte, there can be no galvanic corrosion. (Isn't it super dry out where Idaho-Lefty lives?)

Whatever the exact phenomenon is, I've heard David Tubb says that HBN coating on the bullet prevents it...

 

[SeabeeKen]

Why does the shoulder part of that case not look like brass?

Possibly because no powder or bullet was in contact with it.

I've had bullet weld in 10-12 months. Never checked for it sooner than that. It only happened in brass with clean bare necks. Leaving carbon in the necks seems to prevent it. It is a real thing

 

[ebb]

It was 43 this morning and I have to fix the tractor, so i guess in a bout 30 minutes.

 

[ebb]

Does this condition happen with nickel coated cases? Could the solution be to use them if long term storage is the goal?

 

[Gary in MD]

Yea, it’s not “real welding” but SOMETHING is happening. I have experienced it several times over the years with ammo that has sat for several years. It either didn’t shoot as accurately as it originally did or when I used a kinetic bullet puller, it took 4 times the amount of smacks on a solid surface. I have broken two pullers like this. If it’s never happened to you then that’s fine but it does exist. Hasn’t happened to me in a while, since I don’t let the ammo sit that long and definitely don’t clean the inside of case necks. YMMV

 

[wildcatter]

I simply use a nylon cleaning brush to brush my case necks before seating and never clean more than that after fireforming new brass. I don't believe you ever have to worry about such trivial issues loading this way. But I don't try make them pretty, just accurate.