Question:  I have some older Sennheiser HMD 410-6 headsets that I would like to convert for use with Clear-Com RS-701 beltpacks that use a 4-pin XLR connector.  Can you provide the proper wiring pinouts to a 4-pin XLR-F connector?
Answer:  Traditional ClearCom headset connector pinout:
XLR Pin 1 - Mic ground
XLR Pin 2 - Mic signal
XLR Pin 3 - Earphone ground
XLR Pin 4 - Earphone signal

Assuming the wires on your HMD 410-6 look similar to this 
Left earphone: yellow (+) and black (-)
Right earphone: red (+) and black (-)
Microphone: shield = ground, inner conductors are mic.
Assuming the wires on your HMD 410-6 look similar,
here is how to wire it to a 4-pin XLR-F connector:
XLR Pin 1: shield and one of the inner mic wires
XLR Pin 2: other mic wire
XLR Pin 3: black wires from both headphone
XLR Pin 4: remaining (yellow & red) wires from headphones