RickB,
This is why you use a small slightly carburizing flame. The small is so you can localize the heating. The slightly carburizing is so you do not remove carbon from the steel. You concentrate the heating on the cocking cam surface and harden only this area not the whole back end of the bolt. You can easily heat the cam to hardening tempurature without getting the handle joint too hot. BTW, that temperature for the flowing of the brazing is correct and is the reason the cocking cam is so soft. Once you reach flowing temperature, you are approaching the temp required to anneal 4140. If the furnace is a bit hot, the camming surface is too soft.
The cocking piece on the Remington IS hard but the cocking cam is sometimes so soft that it is very sticky. I have seen the nose of the cocking piece broken off in extreme cases.
You see the same sort of situation on Mauser bolts on which the handle has been welded and the cocking cam annealed as a result. It is proper procedure to re-harden the cam. I recently made a replacement bolt for a 40XBR of mine. I made the boltbody of plain carbon steel in the annealed state. I was out of acetylene and didn't have time to get to town prior to the shoot so I just lubed it and went. Not surprisingly, it was pretty sticky. When I got back home and got more acetylene, I hardened the cam and the cocking effort was halved.
Post 64 Winchesters occasionally have the same problem as the Remington. Little can be done with them since the brazed joint is right in the middle of the cam.
I once tried the addition of a hard surface bronze to the Winchester cam and this worked very well but was such a pain to apply that I decided not to offer it as a service. This brazing produced a nickel/bronze/ silicon matrix which was very slick but also very expensive and fussy to use. GD
