Marine M-27 Infantry Automatic Rifle Reliability Testing Results

The ultimate winner of the Marine Corps M-27 Infantry Automatic Rifle contract was the the HK M27 IAR, a version of the company’s HK 416 AR knock-off.  A friend of a friend of the blog FOIAd this information, which took him two requests.
The first produced the Round One reliability testing, which downchecked 6 of the 10 submissions. During the first-round test and data analysis, the submissions were blinded by using a code letter ID from A through J. In the results below, the producers of the four proposals which advanced to Round Two are shown, while the downchecked candidates are still indicated only by code letter.

Results from Round One, in 2008:

e. All participants submitted three samples for testing.

f. Results for all Class I and II failures are listed below across all 3 UUTs from 9 of the 10 IAR Bid Samples.

  1. Colt proposal A: 60 Failures
  2. Colt proposal B: 28 Failures
  3. Competitor C: 23 Failures
  4. Competitor D: 78 Failures
  5. Competitor E: 39 Failures
  6. Competitor F: 12 Failures
  7. Heckler & Koch Defence Inc. proposal G: 27 Failures
  8. Competitor H: 124 Failures
  9. FN Herstal proposal J: 26 Failures

g. The 10th IAR Bid Sample, Competitor I, was determined unsafe for live fire due to a lack of proof marking. Live fire testing was not conducted.

Kind of a raw break for that unfortunate competitor, Code Letter I.

Note that some of the rejected proposals (C, E, F) had fewer failures than the ones that proceeded. This is presumably due to the distribution of the failures. (If you have only a few failures, but they’re take-the-gun-to-the-bench failures, that’s a whole other thing than a higher quantity of simple failures that are rectified in seconds by operator immediate action (a la SPORTS drill on the M16/M4 series).

This is the Round One definition of failures by class:

Reliability Testing

The Unit Under Test (UUT) shall have a Mean Rounds Between Failure (MRBF) of 900 for Class I and II failures combined (Threshold), 5,000 MRBF (Objective).

  1. Class I failure: A failure that may be immediately corrected by the operator within 10 seconds or less while following prescribed immediate action procedures.
  2. Class II failure: A failure that may be corrected by the operator, and that requires more than 10 seconds but not more than 10 minutes to correct (less the TM/OM defined cool down period if a hot barrel condition exists).  Only the equipment and tools issued with the weapon may be used to correct the failure.

A very similar definition of failures, with a third, more serious, class, was used for Round Two in 2009.

This table is taken from the FOIA release, but we have added a column identifying the firearms, which in this test were coded 09 (presuably for the fiscal year) and a letter, thus 09A, 09B, etc.

UUT Manufacturer MRBF
Class I and II
Class III
Barrel Life
09A Colt 952 60,000 1800
09B Colt 1,277 15,000 1400
09C FNH USA 5,000 N/A* 5,200
09D HK USA 1,622 20,000 16,200

Some interesting results here. The FN entrant had the highest rate of relatively minor Class I and II failures, but the lowest rate — zero — of Class III failures. (That’s why it’s “N/A”. You can’t calculate an MRBF with zero failures). And the HK example was distinctly mediocre compared to these competitors, on this one measurement. Conversely, it had far and away the highest barrel life — an important statistic for the always-broke Marines.


Apologies to all for leaving off the document. This was actually two separate FOIA releases, of three and two pages, but I’ve combined them into one document and OCR’d them for your convenience (well, I also OCR’d them so I could pull those quotes above).

The initial page with the ID of the requestor has been deleted as he has requested privacy.

IAR Reliability Testing FOIA Release.pdf

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