Cold Weld, fact or fiction?

[ohiohunter]

What do you guys think? Is cold welding a reality or not? If so, how long does it take to set in?

 

[FearNoWind]

Oh ... you're apparently referring to cold welding of bullets to cases rather than the actual commercial use of the process.
My mistake ...
If by "cold welding" you mean galvanic corrosion then yes - it certain as a reality.
Brass is a composition of copper and zinc. Depending on the atmosphere, galvanic corrosion can be rapid or slow but eventually there will be a corrosive bonding between bullet and case.

 

[ohiohunter]

How long would you say it takes for a bullet to cold weld to a case to the point of significance?

So If I have a one hole gun and I shoot a 5 string group, but 2/5 were old loads and the other 3 were loaded right before I shoot. Will the 2 old loads show a different POI?

 

[Mikecr]

I don't know the root cause but there are factors(a combination) leading to an increase in static friction(stiction). Don't confuse it with normal increasing of bullet grip over time, as necks continue to springback from expansion of seating.

Tell you what; I'll sell you the solution for 1cent/shot & trust you to pay me for application of it
It's carbon film,, Yep, that hi-tech stuff left in your necks on firing. If you don't wet lube bullets with water soluble case lube and stop cleaning away the magic carbon film, you will never run into the condition considered cold welding. Ever.
With the carbon film, your seating forces will be more consistent and with that your seating depths will be more consistent(I should charge 3cents/shot).

These folks so proud of squeaky clean case insides, are setting themselves up for cold welding, inconsistent seating forces, and inconsistent seating depths. And for no gain whatsoever.
They are funny people..

 

[gohring3006]

I don't know the root cause but there are factors(a combination) leading to an increase in static friction(stiction). Don't confuse it with normal increasing of bullet grip over time, as necks continue to springback from expansion of seating.

Tell you what; I'll sell you the solution for 1cent/shot & trust you to pay me for application of it
It's carbon film,, Yep, that hi-tech stuff left in your necks on firing. If you don't wet lube bullets with water soluble case lube and stop cleaning away the magic carbon film, you will never run into the condition considered cold welding. Ever.
With the carbon film, your seating forces will be more consistent and with that your seating depths will be more consistent(I should charge 3cents/shot).

These folks so proud of squeaky clean case insides, are setting themselves up for cold welding, inconsistent seating forces, and inconsistent seating depths. And for no gain whatsoever.
They are funny people..

Dang it!!! My last loads I took a ,30 cal bronze brush and cleaned every one of my case necks. Thought i was doing something productive LOL....

 

[Mikecr]

An endeavor to understand is in some way productive.

If fired cases came out of chambers totally clean, we would have & eventually solve associated issues by pre-fouling our cases with graphite, or tungsten,, or carbon.
This is just what we do after cleaning gun metals to shiny. We foul our barrels, dip necks, coat bullets, etc.