The M855A1, The Whole Truth
The M855A1 cartridge significantly increases chamber pressure (59,160 PSI vs. 51,522 PSI for M855) to achieve M4A1 carbine velocities, leading to accelerated barrel wear and reduced service life. It requires specialized magazines like the EPM or PMAG Gen 3 due to its projectile design and feeding characteristics. While offering improved penetration over M855, its overall effectiveness is debated due to these drawbacks.




![5.56mm [Part II] - M193 vs. M855 Green tip](/_next/image?url=https%3A%2F%2Fi.ytimg.com%2Fvi%2F6Iu-_TkpfO8%2Fhqdefault.jpg&w=3840&q=75)




