The Enfield rifle and bolt were completely disassembled once per year by the Armourers during their yearly teardown inspection. If the firing pin became a loose fit in the cocking piece the Armourer would swedge or slightly compress the last two or three threads on the firing pin. This swedging or compressing of the threads was done with the firing pin extending out past the the rear of the cocking piece.
In plain English the last couple of threads on the firing pin are smashed, crushed and slightly deformed.
Now for the secret hints for firing pin removal
1. Place the cocking piece in a padded vice and tighten down the cocking piece in the vice.
2. Now while pushing "down" hard on your firing pin tool "thighten" the firing pin and make the swedged threads protrude from the rear of the cocking piece.
3. Place a drop of oil on the threads sticking out at the rear of the cocking piece.
4. Now rotate your tool counter clockwise to remove the firing pin, STOP when it starts getting tight and then turn your tool clockwise. Keep working the threads in and out, back and forth reshaping the last two or three threads until you can remove the firing pin.
PLEASE NOTE: The prongs or fingers of your disassembly tool will BREAK OFF if you tilt the tool at an angle and are not pressing down hard.
Press down hard and keep tool parallel to the firing pin.
Guaranteed way to break the prongs or fingers of your tool, out of slots and cocked at an angle.
Don't ask me why my tool is two broken sets of prongs shorter or how I got to be such an "expert".
If you try and remove the firing pin by holding the bolt in one hand and turning the tool with your other hand YOU too can become a broken tool expert. (Clamp the cocking piece in your vice and don't allow the bolt to move)