The Sig 320 is the most tested and selected handgun in the 21st Century.  The advanced modular design won the Army’s Modular Handgun competition and became the M-17 and M-18. After extensive testing involving over one million rounds, the Sig 320 was selected as the new Immigration and Customs Enforcement duty handgun.

Recent internet tales about the M-17 may seem alarming, but they are nothing more than the story of the U.S. Army and the Department of Defense thoroughly testing their new handguns. I fired the M-17 at SHOT and found it well designed.

I have four Sig 320s. None of my 320s are exactly the same as the M-17, but they share many features. Today I went to the range and fired 500 rounds through them collectively, using a variety of ammunition. I had a single failure to lock the slide open on the last round.

I have complete faith in the Sig 320 family and think they will be even better after the Army rings them out. The guys at DHS are shooting their 320s and seem quite happy with them.

There have been several recent stories about the Sig 320. The 101st Airborne and the 1st Security Force Assistance Brigade have fielded the M-17. There were YouTube videos of dropped 320s firing and now there is the Annual Report from the Department of Defense Director of Operational Test and Evaluation (DOT&E).

I read the report so you don’t have to. The DOT&E report list some issues and describes the solutions. Some problems are already fixed, others aren’t as bad as they seem. Let’s take the issues as they came up in the report:

During drop testing in which an empty primed cartridge wasinserted, the striker struck the primer causing a discharge. SIG SAUER implemented an Engineering Change Proposal (ECP) to correct this deficiency by implementing light weight components in the trigger group mechanism.
This has been corrected in all of the Army handguns and Sig is in the process of “up grading” all of the other 320s. Two triggers broke after the upgrade, I am sure Sig has addressed that too.
Both the XM17 and XM18 pistols experienced double-ejections where an unspent ball round was ejected along with a spent round. Due to the increased frequency of occurrence during Product Verification Test (PVT), the Army stood up a root cause analysis team to identify the cause of the double ejections in parallel with continued PVT. As of this report, this analysis is still ongoing.
I have never seen this happen in thousands of rounds I have fired in the Sig 320 and the M-17. It seems to happen only with the XM1152 Ball cartridge which uses a 115 grain truncated nose full metal jacket projectile, not the XM1153 Special Purpose cartridge (which uses a 147 grain jacked hollow point projectile) selected as the combat ammunition. I wonder if the short bullet is causing a feeding problem.
Some reports have taken issue with the legality of hollow points in war. This has been dealt with quite clearly by the Army lawyers.
For the next part we need to understand the terms the Modular Handgun System test used:
For the MHS, a stoppage is defined as any deficiency that prevents the pistol from operating as intended, but is corrected through immediate action. A failure is defined as a hardware deficiency that requires replacement or repair. Slide stoppages accounted for 50 percent of XM17 stoppages, and 75 percent of the XM18 stoppages observed during Initial Operational Test and Evaluation (IOT&E). In these stoppages, the slide failed to lock after users fired the last round in the magazine.

During PVT, the XM17 with ball ammunition met its requirement for Mean Rounds Between Failures but not its requirement for Mean Rounds Between Stoppages.

During PVT, the XM17 and XM18 were tested for MRBF and MRBS with special purpose munition and with ball ammunition with testing out to the required service life of
25,000 rounds per pistol.
The Mean Rounds Between Failures reliability requirement is 5,000 MRBF for a 98 percent probability of completing a 96-hour mission without a failure. The Mean Rounds Between Stoppages reliability requirement is 2,000 MRBS for a 95 percent probability of completing a 96-hour mission without a stoppage.
The XM18 with ball ammunition did not meet its MRBF or MRBS requirement.
The XM17 demonstrated 6,944 MRBF (99 percent probability)
The XM18 demonstrated 3,906 MRBF (98 percent probability)
The XM17 demonstrated 343 MRBS (75 percentprobability)
The XM18 demonstrated 197 MRBS (61 percentprobability)

The failures look pretty good, but the stoppages seem excessive. Here is the issue:

The predominant cause of stoppages was the failure of the
slide to lock (FSLR) after the firing of the last round in
the magazine (60 of 120 stoppages for the XM17 and 63
of 85 stoppages for the XM18). The purpose of the slide
locking to the rear is to inform the operator that the last round
has been expended, and that the operator needs to reload a
magazine into the weapon. Operators who are trained in
pistol qualification, as taught by the Army marksmanship unit,
utilize what is known as a high pistol grip. This grip places
the non-dominant hand along the pistol slide on top of the
slide catch lever. Many operators stated that the placement of
the slide catch lever caused them to engage it while firing the
pistol, which resulted in the slide not locking to the rear when
the last round was expended in a magazine. Sixty percent
of all FSLR stoppages (75 of 123) were experienced by
8 shooters out of the 132 who participated in the IOT&E.
The Army Marksmanship Unit experts stated that this is an
insignificant problem that can be mitigated with training and
experience with the weapon.
I though this was worth mentioning. Not sure why they picked 35 yards:
The MHS met its accuracy requirement that 10 shots at 35 meters can be covered by a 4-inch disk, with the center of the grouping being no more than 4 inches from the point of aim, 90 percent of the time. This was an entrance criterion for the IOT&E.
I respect the Department of Defense process. Through the life time of the M-17, there will be constant testing and improvements. The annual report shows no issues which have not or cannot be resolved. The shooters at DHS who selected the Sig 320 as their weapon are also providing feedback.
The Sig 320 family, like all weapons systems, will have issues and receive up grades. I believe that it will become the standard handgun for the military and law enforcement.
Photos courtesy of the U.S. Army.

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