Practical Material Penetration of M855 and M193

The Ammo we will be testing

Since we seem to be hurtling closer to a civil war every day it would be prudent for you to know what you can shoot through and what you can hide behind. So we’ll be examining various types of cover to determine how effective different types of rounds are against them. To begin we’re going to be looking at some common types of 5.56 ammunition against varying thicknesses of steel plates. We’ll be using M855 and M193 for these tests.
M855 and M193 are some of the most popular and widespread rounds in the US today. With such ready availability they would be very likely to end up your rifle and for that reason they make great candidates for testing.

The Gun

Due to the popularity of M4 style AR-15s we’ll be using a Ruger AR-556 with a 16 inch barrel to conduct the tests


Shots were made at a distance of 27 yards. All targets are mild steel and with the exception of the last plate in the ¾ inch stack have not had any significant alterations which might affect the test (the last plate in the ¾ stack has several weld beads on it). Some thicknesses were met by combining two plates to double the total plate thickness, these plates were clamped together. All targets were held in a drill press vice.

1/8 inch plate



¼ inch plate



3/8 inch plate



½ inch plate

M193 – Bad Shots



½ inch plate review

¾ inch plate



¾ inch plate review


1/8th inch and ¼ inch plates offer practically zero protection from either of the bullets and create dangerous secondary projectiles and spalling. It might be better to avoid this type of cover in its entirety due to the secondary projectiles. 3/8ths inch plates may offer you some protection, especially against lower velocity rounds such as M855 but will not stop faster moving bullets such as M193. ½ inch plates and up offer consistent protection and are ideal for cover. It should also be noted that the further the bullet has to go to reach the plates the more effective they are at stopping the bullets.  Examining the rounds themselves it appears that M855 projectiles do not affect the target in a consistent way, with some penetrators separating from the rest of the projectile and some sticking together the whole way through the target. From these results it seems M193 is the better round for penetrating steel barriers. Additionally the effects of spalling and fragmented bullets are devastating and must be a factor in cover selection and when selecting body armor.

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2 Responses

  1. Craig says:

    I have done this test myself and found the same results: M193 is superior in virtually all uses and costs less.
    Also, M193 does a vicious job on tissue while M855 tends to leave holes.
    The reputation of the M16 was created using M193. I have seen pictures of M80, 308 ball, and M193 head shots. The M193 took the head off. Quite the reputation.

  1. January 3, 2021

    […] Practical Material Penetration of M855 and M193 […]

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