Colt TWO TONE magazines - pre WWll

Aside from being a S&W collector, I also have a bunch of Colts - mostly Automatics. Most of the Colts I own are older pre WWll guns and came with at least one "two tone" magazine. I always wondered why they were two tone and purposely left in the white on the upper half. Well today I found out......

Before WWll Colt used a bluing method referred to "Gas Bluing" on their magazines. Apparently, that bluing process took some of the temper out of the magazine lips which is the most critical area of an Autoloader's magazine. To restore the temper to the lips, Colt dipped the magazines into a cyanide bath at 1475 degrees F. for three minutes and that is why the magazines were two tone. During WWll Colt had to mass produce magazines and so they came up with other methods of bluing and Parkerizing.

Well now I know and I thought it was interesting enough to pass on since I am sure there are other "Pony" fans here as well.

Regards,
Chief38

Thanks Chief. I had often wondered the same thing.....I learn something new every day around here....you guys are great!

Thank you for the information. I myself always wondered about the 2 tone magazines. Some many of the forums get into verbal arguement about which product is better. I try to avoid these topics. This type of information is why I cruise the forums.

That's why I like it here. Thanks!
f.t.

Interesting info. Thanks for posting.

Good info. I always wondered about that on my 1930 Woodsman. Thanks. Dick

Since I have both the two tone and all blue magazines for my early Colt Auto's I can honestly say there is no discernible difference in their functioning. The only thing is that the two tone magazines are verified original to the gun, different looking, a bit nostalgic, expensive and will usually get some looks and questions from fellow shooters. I like the idea of knowing I have original magazines that came with guns that are almost 90 years old.

Chief38

That cyanide dip sounds familiar. Isn't that how Glock hardens their slides? They boil it in salts of some sort & IIRC it's some pretty nasty stuff?

I read also if there is no markings on the bottom of the two tone magazines ,they
were made by Colt.??????
Dick

The 'gas bluing' is the oven or Carbonia bluing method used by Colt, S&W and most all the other mfg'rs. It operates at around 850F so it anneals many heat treated steels and it did the sheet metal magazines leaving them almost dead soft.
(Before the mechanized American Gas Furnace Carbonia method, Colt used the charcoal blueing method which was a very hand labor intensive practice over an open hearth of charcoal. A few very early production 1911's were done that way IIRC)

The cyanide hardening bath was a form of case hardening. It was done to frames (not by Colt) and other parts. Remington used it to some extent in production. The case colors from cyanide are different than charcoal case colors and are generally identifyable when placed side by side.
When the thin sheet metal magazines were dipped in the molten potassium cyanide, pulled out and quenched in oil (not water), the thin metal was hardened through to an extent that left it still a bit flexable, not brittle. Had they quenched in water, they would have been brittle from through-hardening,,and I suspect would have had nice case colors on them.

They called the process a 'tempering', though perhaps it was a hardening and draw at the same time. The bluing process having removed the original spring temper of the mag, this was just adding some back to it.

Early mags were done about an inch down from the top, then later down to below the mag catch slot so as to make that wear better.

The treatment removed the blueing originally done leaving the 2-tone look.

Commercial mags got the same treatment.

Springfield Arsenal made magazine (WW1) used to cyanide harden the entire completed magazine (oil quench) then draw back the hardness from the top feed lip area by tempering in oil in the 400 to 500F range.
Then they'd Nitre Blue (molten Potassium Nitrate dip) the bottom half of the mag for color. Nitre Blue runs around 650F.
Different ways to the same end.

In the late 30's, hot salt blueing was coming into use in the industry. Winchester switched in about '38.
Du-lite was the trade name of one ofthe processes and it's still around.
Pentrate (sp?) was the other. I think that one became the commercial blueing known as HeathBath but could be wrong.
Colt used Du-Lite also for finishing on WW2 magazines. At just over 300F, the hot salt bath doesn't remove any heat treatment from the mags and they remain a full blue color. No need for the cyanide after treatment.
The contractors used it too in WW2.

I'm not sure of all the contractor codes but it seems the Colt mfg Military contract magazines during WW2 were unmarked.
Contract mags made for Colt had a small C with the contactors code letter following it stamped on the top of the lip IIRC.

2152HQ: The Colt WW II mags I have, have the letters 'C' a hyphen and another letter on the bottom of the magazine floorplate. Usually the 'other letter" is also found on the top of the toe of the floorplate.