Spare bolt and headspace

[TexasSolo]

I was thinking of picking up a spare bolt just to have in case I ever need it. But will just any old bolt work OK? Should I be concerned about head space? The thought of just throwing a different bolt into the rifle and pulling the trigger sort of scares me a bit.

The rifle is a Colt 6920.

[Iraqgunz]

Please use the ORANGE search button. It's been mentioned numerous times.

[Iraqgunz]

https://www.m4carbine.net/showthread.php?t=105778&highlight=spare+bolt+headspace

https://www.m4carbine.net/showthread.php?t=102389&highlight=spare+bolt+headspace

https://www.m4carbine.net/showthread.php?t=66032&highlight=spare+bolt+headspace

https://www.m4carbine.net/showthread.php?t=64237&highlight=spare+bolt+headspace

https://www.m4carbine.net/showthread.php?t=47034&highlight=spare+bolt+headspace