A MLB fastball leaves the hand around 140 feet per second. For a non athlete with a more ordinary pitching shoulder, that would be more like 110 to 120 fps.
Throwing this tiny speck of a projectile would seem to be significantly more difficult than launching a baseball, as the bullet has essentially no inertia to balance your throwing motion against. I think 100 feet per second would be an optimistic goal.
At 100 feet per second, the 2.3mm SwissMiniGun projectile would have a muzzle energy (or more properly, a palm energy) of about .044 foot pounds - or 0.7 foot ounces.
A baseball at 140 feet per second has about 100 foot pounds of energy.
