you are all right; it was originally use to throw line between ship for rescue operation, to overcome natural obstacle or to reach any place of difficult access. I bought it long time ago as a collector piece and never use it. All the load that come with the kit was shot before I buy it. I don't want to play the guessing work to find the proper load since I will not use it intensively. The picture in the instruction pamphlet show what look like cardboard with short brass base shell, I don't think the full brass 12Ga shell will be needed. A guy suggest to cut a clay target shotshell at 1-3/4" long, removing the pellet, leaving only the back part of the gas piston! Let me know your opinion on that?