Question on Plastic quality of lead under pressure.

[JBMauser]

My question today has to do with the property of lead as it relates to it’s plastic qualities under pressure.  I recently got my Ebay Swag-o-matic into service. 
After making a few bullets from pounded cylinders made from surplus 50cal balls, it occurred to me that  if I wanted to make a heavier bullet I could run the formed bullet back into the press with a 00 buck pellet on top and it would form onto the bullet.  My question is would it form into the bullet or would it always remain a separate piece just swaged onto the bullet.  My gut tells me that the two masses would remain separate even though the plastic action may let them appear to be unified.  I am thinking that only a melt will cause an amalgam (sic) to occur.  But I don’t know if pressure enough to cause lead to flow out a bleed hole can cause an amalgam to occur.  JB

[iiranger]

pressure can create heat... If you reached enough pressure, then the heat would meld the two lead bodies, probably. You donot make extremely clear what alloys you are using... but reaching these pressures in a hand press... I doubt it. Without the huge, factory grade presses, I suspect, yes, the only ready way for you is the torch of some sort... luck  Dave Corbin, on his site(s) have tables in books on the engineering pressures necessary for such things, you might want to browse there...

[jcunclejoe]

Even commercial bullet making presses do not generate enough heat to fuse the two parts together. They would always be seperate peices of lead until at least the lowest melting point of the alloy was reached.
Speer uses something along those lines in one of their bullets, IIRC it is the Grand Slam where they swage hard lead into the rear of the jacket and they make a pocket somewhere in the process. Then molten lead is injected into the pocket and fills up the rest of the jacket. The molten lead and the pocket help keep the two parts together by partially melting the surface of the hard lead and effectively bonding them together. It may not be a complete bond though since they still use the pocket (mechanical lock) to help hold things together. The molten lead also "grips" the inside of the jacket but does not form a true bond.
Then they swage the bullet to it's final shape.
Thanks
Joe