I have been toying (pun partially intended) with the idea of getting one of these small crossbows but was deterred by both the price versus my priorities, and my uncertainty as to the effectiveness for any actually practical purpose. In other words, it was too much for just a toy if that is all it is.
Does anyone have a link to an archers semi standard formula or table (I assume there is one somewhere) that will take the pounds of pull, the length of draw and the weight of the projectile to give an approximation of "muzzle" velocity for a bolt or arrow? This will not be a linear formula, I don't think, so a 25 pound pull with a 2 foot draw will probably not have the same velocity on an equal weight projectile as a 50 pound pull with a 1 foot draw, and I am probably being very overly generous with a 1 foot draw for these small crossbows..
Once the "muzzle" velocity (can someone also help me out with the proper term for this in archery?) and the weight of the projectile are known then we have the projectile's kinetic energy. I also assume that there are tables or formulae for calculating trajectories, fall of projectile, drag, delivered energy at different distances given weight and velocity.
There should also be some table/formula suggesting the relationship between kinetic energy or mass and velocity of the shaft or arrow and the expected penetration on various targets/species given a type of point.
Since the crossbow bolts have a different form factor than arrows, the standard wisdom of arrow flight will not apply perfectly, but should give us a ballpark.