The Navy “Approach” (the Naval aviation safety magazine) in July 1971 has an article on Pyrotechnic Signals for Pilots for survival use as John mentions. They are listed as follows
Mk 139 Yellow
Mk 140 green & red
Mk 121 Red
Mk 122 Green
Mk 123 Yellow
All of these flares were originally produced for Navy Survival.
The original 9mm development was done at the Crane Naval Armanent Depot in Indiana. All the rounds encountered from Crane had yellow and white tips and R-P headstamps. The initial production contract was given to Explosive Devices Inc in Kiln MS who produced the yellow and white tip rounds with the IVI headstamps, but their production of the red and green flares could not pass qualification and the contract for these two variations was given to Dela Enterprises Inc in California. These are the loads with the WCC headstamp.
I don’t know the story on the 38 Special Flares, but from the looks of them I suspect it parallels the 9mms.
I thought this stuff had long passed out of use, then two years ago I was given a copy of the 9mm section of NAVSEA SW010-AD-GTP-010 SMALL ARMS AND SPECIAL WARFARE AMMUNITION, 18 May 2004 published by the Navy and in this they describe the three 9mm loads as Signal cartridges “for nighttime signaling and fired from a 9mm Semoautomatic pistol. They are specially designed for use by Sea-Air-Land (SEAL) teams.” It says others who have a need can order these cartridges but there is no mention of aircrew. The cartridge that came with them was the WCC 73 headstamped green signal load identical to the aircrew survival load in my collection. I only received the 9mm P part of the book and have no idea what it says about 38 Special.
I have never seen a purple tip load, but it appears to be a new load as part of this series so the story about the SEALS may be true. The old 9mm survival loads have sure been passed to the SEALS.
I have box labels in both 9mm and 38 Special (somewhere) of the earlier rounds-not the purple tip.