This has been around for a while but I just ran across it and thought of you guys.
The following taken from the USCG Notices:
25MM Aerial Signal Launcher Converter Notice
Notice For Owners of 25MM Aerial Signal Launcher Converters (Pre-1997)
Certain customers of Orion Safety Products (or Orion’s predecessor Olin) utilize a metal “converter” to launch 12-gauge aerial signals out of a 25MM launcher. In 1996 the converter was altered slightly to allow for a larger star to increase brightness and improve flight dynamics. In 2005 Orion introduced the 12-gauge HP which was a longer shell designed to improve altitude. While all converters sold since 1996 accept the 12-gauge HP shell, it has recently come to the attention of Orion that converters manufactured before 1996 (whether by Orion or Olin) will not accept the 12 gauge HP shell.