Hi All,
I have a Craftsman Industrial 3/8" electric drill (variable speed,
reversible) with keyless chuck (model 315.271490 if you must know). I am
unable to remove the chuck according the instructions, which have me locking
in an allen wrench and hitting it clockwise with a mallet, then removing the
chuck screw by turning it clockwise, and so on.

1. I must be missing something obvious because hitting the allen wrench does
nothing except rotate the chuck. The chuck is basically free to turn so how
exactly am I supposed to be loosening anything with this task?

2. On turning the chuck screw clockwise with a screwdriver to remove it,
looking down the middle of the chuck I cannot discern any actual screw down
there.

Any advice on the above much appreciated. I am not a power tool newbie but
I feel like one in this particular case.

Thanks,
Howard