Mean Rounds Between Stoppages for Colt 6920?

[lysander]

Woah. That's actually very impressive in my opinion. If military M4s are doing that with M855A1, I feel pretty good about the MRBS of my LE6920. As far as Crane's criteria, this is everything I could find on it: http://soldiersystems.net/2018/05/14...d-performance/

Do you have a source for that test the Army did in 2016? I don't doubt it, I'm just curious to see the details for myself.



Understood. Yeah, mine ejects about 0230 or so. I've never shot it suppressed, though. From my experience I've never shot a suppressed AR that wasn't overgassed. Seems like if it's not overgassed with unsuppressed, it's going to be overgassed when suppressed; and if it's not overgassed when suppressed, it's undergassed when unsuppressed.

I will replace parts at the recommended intervals for preventative maintenance for my 6920, so the faster parts wear doesn't really bother me.

Its not available on-line, but it's the 2015 Re-Baseline Reliability Test 5.56mm Weapons using M855A1

[SouthwestAviator]

Its not available on-line, but it's the 2015 Re-Baseline Reliability Test 5.56mm Weapons using M855A1

How did you learn of this? I'd be really interested to read about that test's findings in detail. Is there any way non-military can obtain this information since it's not online?

I'm aware this might not be the most reliable source, but according to cited "weapons officials" in the Army, the M4A1 had 1691 MRBS.

"It’s still unclear how close any of the competitors came to reaching requirement 3,592 mean rounds between stoppages. Weapons officials did say that the M4A1, the special operations version of the M4, achieved 1,691 mean rounds between stoppages when it the tested using the new M855A1 ammunition."

https://www.military.com/daily-news/..._todayinmil.nl

Are you sure the 3,592 MRBS wasn't the requirement for the Individual Carbine program rather than the actual recorded number of MRBS?



Strangely, I've also found a document from 2009 where the Army supposedly said the M4 was going over 3600 MRBS.
http://www.peosoldier.army.mil/docs/...r-Oct%2009.pdf

Since the IC program required a reliability rate higher than this number, perhaps they were using a requirement from before the M855A1 was adopted, which M855 was what the competitors designed the guns to shoot. That's speculation on my part, though.

Overall I'm pretty confused. These numbers are coming from somewhere but are conflicting.

[lysander]

How did you learn of this? I'd be really interested to read about that test's findings in detail. Is there any way non-military can obtain this information since it's not online?

I'm aware this might not be the most reliable source, but according to cited "weapons officials" in the Army, the M4A1 had 1691 MRBS.

"It’s still unclear how close any of the competitors came to reaching requirement 3,592 mean rounds between stoppages. Weapons officials did say that the M4A1, the special operations version of the M4, achieved 1,691 mean rounds between stoppages when it the tested using the new M855A1 ammunition."

https://www.military.com/daily-news/..._todayinmil.nl

Are you sure the 3,592 MRBS wasn't the requirement for the Individual Carbine program rather than the actual recorded number of MRBS?



Strangely, I've also found a document from 2009 where the Army supposedly said the M4 was going over 3600 MRBS.
http://www.peosoldier.army.mil/docs/...r-Oct%2009.pdf

Since the IC program required a reliability rate higher than this number, perhaps they were using a requirement from before the M855A1 was adopted, which M855 was what the competitors designed the guns to shoot. That's speculation on my part, though.

Overall I'm pretty confused. These numbers are coming from somewhere but are conflicting.

First, the 2016 report is the testing that established the baseline reliability for the M4/M4A1, the stated purpose of the testing was to establish that baseline, any potential replacement of the M4 had to exceed the M4 in reliability, namely 3592 MRBS. The date of the tests may have been earlier, the report I read was dated 2016. [EDIT: Yes, the tests were completed in 2006-07, the actual report is a list of every single malfunction that occurred, in every single weapon, over the course of testing, and a lot of test methodology.]

Second, 3671 MRBS is above 3600, if just barely. So, the PAO paper linked is truthful, but also a bit propaganda-ish.

And, last I heard the M4A1 is not "...the special operations version of the M4...", at least not since 2012 when regular infantry units began fielding them. So, where did the article (dated 2018) get its info? And, is that info about pre-PIP weapons?

[SouthwestAviator]

First, the 2016 report is the testing that established the baseline reliability for the M4/M4A1, the stated purpose of the testing was to establish that baseline, any potential replacement of the M4 had to exceed the M4 in reliability, namely 3592 MRBS. The date of the tests may have been earlier, the report I read was dated 2016. [EDIT: Yes, the tests were completed in 2006-07, the actual report is a list of every single malfunction that occurred, in every single weapon, over the course of testing, and a lot of test methodology.]

Second, 3671 MRBS is above 3600, if just barely. So, the PAO paper linked is truthful, but also a bit propaganda-ish.

And, last I heard the M4A1 is not "...the special operations version of the M4...", at least not since 2012 when regular infantry units began fielding them. So, where did the article (dated 2018) get its info? And, is that info about pre-PIP weapons?

The 1691 MRBS number is said to have been given out by PEO Soldier officials from some rooting around. Not sure if it's pre-PIP or not, or what magazines they were using.

I do see now where they established the baseline of reliability for the M4A1 at 3592 MRBS from this (on Slide 10): https://ndiastorage.blob.core.usgovc...apons_NDIA.pdf

I'm wondering if the 3592 number came from regular M855 and PEO Soldier's 1691 came from after M855A1's adoption.

This is not a primary source from the government, but according to this, the PMAG tests in 2015 with M855A1 had an MRBS of 4800. I'm looking for a government document showing that number: https://www.thefirearmblog.com/blog/...-m3-magazines/

[SouthwestAviator]

I wanted to say thanks to Lysander for bringing the 2016 test results to my attention. It helped a lot.