Earlier I pointed out that the M4 performed far better in identical dust chamber tests earlier this year than it did against piston-driven challengers more recently:
The M4 fared far worse in this test than in a similar test conducted on the M4s alone earlier this year. 60,000 rounds this summer yielded only 307 stoppages (still more than any of the challengers this time around) in what is described in the article as an identical dust chamber test.
Don’t think that won’t have some conspiracy theorists, um, theorizing.
The M4 suffered 882 failures this time around, and now we begin to learn why the number is so much worse than earlier:
Army testers threw out hundreds of M4 carbine failures from a reliability test this summer, causing the number of Class 1 and Class 2 stoppages, those that soldiers can clear themselves, to drop from 678 to 296, according to an Army briefing document.
You know, this sort of thing could get some of the more excitable sorts a bit, um, excited.
Army officials explained that the 382 M4 stoppages not included in the results could have been discarded when ATEC officials finalized the results of dust test two in October through a process known as the Reliability, Availability and Maintainability, or RAM, Scoring Conference that is part of every such test, said Col. Carl Lipsit, project manager for Soldier Weapons.
The 863 stoppages reported in the results of dust test three represented the final number after the RAM process, Lipsit said.
ATEC officials did not provide test three’s initial number of failures and said the command –stands behind” the 296 stoppages in dust test two that are in the final report, said ATEC spokesman Tom Rheinlander.
I’m not sure why the current discrepancy between 882 and 863 exists, unless only 19 stoppages were RAMed out.
RAM is a standard process which is designed to help remove “duplicate” issues due to the same particular failure mode. This is the example given in the story:
If testers link 10 stoppages to a broken part, they could throw out nine of those stoppages and count only one failure in the final report.
It’s getting murkier and murkier.