I wish that guys would stop trying to deny that cold welding exist. Just because you have not had it happen or did not recognize it does not mean that it does not happen. It in fact does and I have experienced it many times in the last 51 years I have been reloading. I wonder how often a stray shot or one out of the group that is that annoying flyer is in fact a cold welded case and bullet.
Yes 60K psi of pressure can break a cold weld easily but it will have a different point of impact.
There are lots of conditions that cause it and so it is hard to put your finger on. The worse case is where not all the cases and bullets are cold welded the same. As Oldtime experienced. A good way to test is to seat your last years loads a little deeper and if you have a pop or noticed resistance to moving the bullet then you have cold weld.
If you are shooting ammo that has been loaded for a while and get erratic performance then check for cold weld by trying to seat the bullets a couple thou deeper and then test again.
When I started Moly coating bullets my cold welding stopped. There are so many variables to cause this condition. Brass composition, type of bullet jacket, type of lube in neck, environment the ammo is stored in, How long in storage. What happens to the lube in the neck if organic it can turn into gunk or glue with time in hot or humid environment. I could go on and on but you get the picture.
Now I do not use Moly as much as I used to, not sure why, got lazy I guess. Moly does not make a bullet more accurate nor faster, it does allow longer strings before cleaning and it does keep the barrel cooler during long strings both of which are good things and oh yea it also prevents cold welding.