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two tone 45 acp magazines
338magnut
Member Posts: 761 ✭✭✭
Can anyone tell me what was the purpose of only bluing half on some 45 acp Colt magazines hence the name 2 tone. Any info is appreciated. Terrill
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Can anyone tell me what was the purpose of only bluing half on some 45 acp Colt magazines hence the name 2 tone. Any info is appreciated. Terrill
The earlier steels required heat-treating after bending and welding a magazine into its finished shape. Colt did this by heating the upper portion (feed lips) by dipping them in molten cyanide, then quenching (cooling rapidly) by dunking them in oil.
From my reading, Colt originally was doing this process before bluing, but they realized the "charcoal bluing" process used on firearms early in the 20th century (which involved heating during the finishing) was causing changes in the tempering done to magazines' feed-lips, so they changed their practices and started doing the heat-treating of magazine feed-lips after the bluing process. This caused the finish to be lost where the magazine entered the molten cyanide.
My understanding is that it was changes in metallurgy, elimination of the charcoal-bluing processes previously used for finishes, along with changes in tempering techniques, that resulted in magazines no longer receiving a dip in molten cyanide so the two-tone appearance disappeared.
You'll see that "two-tone" appearance applied on modern magazines -- which doesn't involve any heat-treating -- to make magazines look like vintage magazines, sometimes sold legitimately as a reproductions, sometimes as counterfeits.