Tenser's Steady Aim

This spell aids a moving archer, crossbow-man, or arquebusier with a steady shooting hand. No matter how fast the warrior is moving or how unsteady his motion, the warrior suffers no movement-related attack penalty to shots made with device-propelled missiles. The spell provides no bonuses to slings of any sort, nor any bonus to stationary and steady warriors.

The material component is a small coiled spring.