Pick a round and a target, then fire. Slow motion shows the air it shoves aside and what it does when it arrives.
The round sits in front of you as it would come out of the box. Cutaway slices it open; exploded pulls the parts apart. Fire, and the case stays behind while the projectile flies downrange in slow motion, speeding through the empty middle of the range and slowing again for the impact. The gun itself is left out: the projectile simply leaves at the load's rated muzzle velocity.
A projectile shoves air out of its way. Every instant it sends out a pressure pulse that spreads at the speed of sound, about 340 m/s. Slower than sound, those pulses run out ahead of it as rings. Faster than sound, they cannot get out of the way and pile up into a cone: the shock wave you hear as a crack. The faster the round, the narrower the cone; its half-angle is arcsin(1/Mach). The large ring that starts at the muzzle is the blast of the propellant gas.
Energy is ½mv². How far a projectile gets depends on how it spends that energy. A narrow, heavy bullet pushes a small hole a long way. A hollow point opens up and spends its energy early. A pointed rifle bullet often turns sideways partway in, which suddenly makes it much harder to push. Lead shot splits the energy across hundreds of small spheres that each run out of speed quickly.
A shotshell throws a cloud of pellets that spreads sideways (the pattern) and stretches lengthwise (the string), because no two pellets leave at quite the same speed. A tighter choke keeps the pattern smaller for longer. Each pellet here is flown and scored on its own.
Flight uses a point-mass trajectory with the G1 drag standard (sphere drag for shot) in sea-level standard air, aimed so the round lands on the target's center. Fruit and wood use a drag-plus-strength penetration model that lets hollow points expand and pointed bullets tumble. Steel and aluminum use De Marre's ballistic limit. The models are simplified and tuned to sensible ballpark figures: use them to compare and understand, not as test data. Loads are typical commercial specifications with lead-core projectiles.
Space fire, C cutaway, X exploded, A air, R back to the round, / hide the interface. Drag to orbit, right-drag to pan, scroll to zoom.