1100 Firing pin

[Speedbump]

Do the 1100's have different firing pin lenghts like the 11-48? Is the 1100 a inertia firing pin or is it supposed to have protrusion?

[Mainspring]

All the firing pins are the same. If by protrusion you mean the firing pin sticks out the front of the breech bolt, it should not. If it does the usual cause is a broken firing pin retractor spring, the old style ones break in the middle and the two halves screw themselves together resulting in a too short spring. The new style springs have several coils touching each other as reinforcement.