A manually operated rifle capable of firing a heavy-duty round at a reasonable rate of fire. Some armies practiced single-shot fire until the enemy approached to close range, only then switching to the magazine and the higher rate of fire that could be very deadly at short range.
This is weapon changed look and feel of the battlefield more than any other. Every soldier now had a long-range, reliable firearm capable of sustained fire. It ended the age of colorful uniforms and close formations of standing troops, forcing soldiers to seek cover and use camouflage.