Army & Marines at odds over 5.56mm round

Defense News said:

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On capitol Hill, the House Armed Services' Subcommittee on Tactical Air and Land Forces has ordered Defense Secretary Ashton Carter to study the issue and report to Congress by next March whether it still makes sense for the Army to use its M855A1 round while the Marine Corps moves to make the M318 Mod 0 Special Operations Science and Technology round its new standard.

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The problem stemmed from the M855A1's high chamber pressure and exposed steel tip, which could chew up a weapon's feed-ramp, erode barrels and crack bolts, said Col. Michael Manning, the program manager for Infantry Weapons Systems at Marine Corps Systems Command in Quantico, Virginia. The Marine Corps believes SOST is superior "at this time,"

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concerns stemmed from testing showing the Army rounds tended to cause problems like early erosion within a weapon's gas port. This was a particular problem with M4 carbines, which as a consequence cycled faster, especially during automatic fire. That has great potential to induce malfunctions.

This led the Army to consider putting electronic shot counters on its M4s to ensure they underwent maintenance as cracks appeared. That could happen after the weapons fired 6,000 rounds. In some cases, however, cracks appeared after firing as few as 3,000 rounds.

Meanwhile, the round's exposed steel penetrator was gouging carbines' feedramps as their bolts fed rounds into their chambers. Gouged feedramps and cracked bolts can cause jams and major malfunctions, potentially taking a Marine or soldier out of the fight.

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skidmark said:

I wonder why neither the Army nor the Marine Corps are bothering to look into the cleaning standards imposed on servicepersons? Starting with the effects of repeated clanging of steel cleaning rods against the feed ramp, chamber and bore.

stay safe.

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