The inner diameter of the plunger tube.
The length, diameter, and wire thickness of the spring.
How far the plunger head travels from a cocked to at rest position.
If you happen to have these figures on hand, or don't mind opening your crossbow up and measuring that would be great, but some fairly accurate guestimations are welcome as well.
Edited by userjjb, 20 May 2005 - 03:12 AM.