http://www.dote.osd.mil/pub/reports/FY2017/pdf/army/2017mhs.pdf
There are some interesting points made about SIG's XM17/18.
During drop testing in which an empty primed cartridge was
inserted, the striker struck the primer causing a discharge.
SIG SAUER implemented an Engineering Change Proposal
(ECP) to correct this deficiency by implementing lightweight
components in the trigger group mechanism. This fix may
have contributed to the splintering of two triggers during the
IOT&E.
Drop testing would have been done in second phase, which didn't happen. SIG Sauer came up with solution which was later implemented for P320. But that solution may have been the reason why there was splintering of two triggers.
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.
Also, the report says the pistol had double ejections. This is when the empty casing is ejecting, a live round also ejects with it. Seems impossible, but when magazine lips have problems, this could happen. Furthermore,
The frequency of this occurrence increased
as more rounds were fired through the pistol.
And it seems like XM17 didn't handle the new FMJ round military is using well. The new FMJ/ball round has truncated cone that looks like the Special Purpose ammunition(JHP).
Several reliability stoppages were observed with both the
XM17 and XM18 when shooting ball ammunition. The ball
ammunition was not included in the IOT&E because of the
demonstrated reliability problems during PVT and the ongoing
root cause analysis.
During PVT, the XM17 with ball ammunition met its
requirement for MRBF but not its requirement for MRBS.
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 percent
probability)
- The XM18 demonstrated 197 MRBS (61 percent
probability)
Army has until Sept. 2018 to decide to go with XM17/18. To those who are more historically knowledgeable, M9 Beretta had some problems of their own during this time. One of the most infamous example is the slide cracking and flying back. This was blamed on metallurgy as well as using ammunition that was far hotter than usual one. Beretta did come up with a solution that will stop the cracked slide from flying back as well.
It will be interesting how this will go. If the SIG Sauer can come up with solutions that address the above problems, it won't have much problem. But if not resolved, it will be interesting development.
Also, user error accounted for 50% and 75% of XM17 and XM18's stoppages, respectively. These were failure of the slide locking back caused by shooter. Remedy is better training.
