Bluing barrel before or after installation?

[ronniet]

I have often wondered how and why of bluing a barrel and action either before assembly or after?
Over the years I have done it both ways, I m not a fan of either, although I do prefer to installing everything after bluing and carding.
I generally rust blue , when I build a rifle or pistol, I hand fit and repair or build each part and fit up everything and check for function of it all and then take apart, clean inspect and bring to grade of finish I want, then blue and card it all, clean and oil and assemble.
On the bolt guns I usually scratch to some degree the barrel when installing.
I often do plug my barrels with rubber plugs but have had them come out during the process.
Also , I use a metal barrel vise with aluminum bushing, powdered rosin and thin lead shims for the right pressure,
I use a action wrench to slam with a shop hammer,
Is there a way I could use a torque wrench with a Mauser action?
any replies will be helpful,
Ron

[M-Tecs]

Don't know if they make these for Mauser but this it the type wrench that is used for using a torque wrench on actions.

http://www.pmatool.com/panda-and-rem...action-wrench/

[405grain]

I just put a barrel on a 93 Mauser on Monday. I fit all the parts ahead of time, then rust blue them individually. After they're blued I put the barrel on. I leave the barrel short chambered and finish chambering once the barrel and receiver are together. I don't use lead, wood or rosin in my barrel vise because those things just let the barrel slip when really heavy loads are applied, (mostly for removing a barrel rather than installing one). I've found that if the aluminum inserts in the barrel vise fit nicely to the barrel, just adding a piece of paper between the barrel and the aluminum keeps the barrel from rotating, and doesn't leave any marks on the barrel.

[John Taylor]

What 405grain said, I use paper between the barrel and block to keep from hurting the blue. A good fitting block is important.