If firing the M20 at the rapid rate, how often do you change barrels?

When firing the M20 at a rapid rate, the correct frequency for changing barrels is every 2 minutes. The importance of this practice lies in managing heat build-up during sustained fire. Machine guns, such as the M20, can overheat quickly due to their high rates of fire, leading to potential damage to the barrel and a reduction in accuracy due to thermal distortion. By changing the barrel every 2 minutes, gunners can ensure that the barrel remains within safe operating temperatures, which enhances reliability and maintains performance during engagement. This practice is part of proper gun maintenance and operational effectiveness, allowing the crew to sustain firing without compromising weapon integrity.

Other options, such as changing the barrel every minute, every 5 minutes, or every 10 minutes, do not align with the established training protocols for maintaining optimal firing conditions and managing barrel wear effectively.