Quote:
Originally Posted by msinc
...the receiver on most post 64 guns is made of a type of cast iron that is hard to even blue much less weld.
|
I hear this a lot and it's incorrect, or at least imprecise.
The issue with the post-63 Model 94s is that they used a sinter forged process for their receivers. This process creates the alloy by mixing the metals as very finely ground powders that are then placed in a mould and formed under intense heat and pressure. The results are just fine in term of strength, hardness, durability, etc, and the advantage is that the forged part is produced very close to the final dimensions so less machining is needed.
The problem was that the alloy had a high percentage of chromium in it that results in a reddish to plum purple color when it's blued by conventional means.
Consequently Big W had to do something different and over the years Winchester used three separate blackening processes in the post-63 Model 94s:
Mfg. Date Serial Numbers Blackening Process
1964-1968 2,700,000 - 3,185,691 Du-Lite 3-0 Process
1968-1972 3,185,692 - 3,806,499 Black Chrome Plate
1972-1981 3,806,500 - 5,024,957 Win Blue/Oxiblak
The 1972-81 receivers that were Win Blued, were iron plated first, and then blackened with Du-Lite's Oxiblak. This is where the "iron receiver" beliefs some into play. These are also the receivers that often end up with a mottled purple finish when re-blued as the iron plating gets polished off in some places but not others.
In any event, once the original finish is removed, any of the 1964-1981 receivers can be refinished with the Du-Lite 3-0 Process.
Once USRACO purchased the plant, they switched to 4144 steel on the AE models and finished them with the normal Win Blue process.