The Naval Surface Warfare Center - Crane (NSWC-Crane) recently ran a test on behalf of United States Special Operations Command (SOCOM) that evaluated KeyMod and M-LOK weapon accessory attachment systems.
NSWC-Crane based testing off of commercially available rail systems that offered Keymod and M-LOK attachment abilities. The testing included Keymod and M-LOK variants of Aero Precision, Midwest Industries, and Seekins handguards and the rail systems were evaluated for repeatability, endurance, rough handling, drop testing, and static failure load.
The testing revealed that the repeatability testing, measured in MOA, of the KeyMod demonstrated a point of aim shift from 0.2 to 14.6 where as the M-LOK demonstrated a 0.0 to 6.6 POA shift. Both systems passed endurance and rough handling tests. Drop testing revealed that the KeyMod slots fractured between utilized slots and the adjacent slots, where as M-LOK attachments observed rearward movement but no fracturing between slots. With failure load testing that attempted to pull accessories off the rail from 90 degree off-axis NSWC-Crane noted a 215% increase of sustained load of M-LOK over KeyMod.
This sample size was limited, but it did provide enough information for SOCOM to choose a path forward. The test concluded that M-LOK maintained better repeatability to maintain point of aim and better rail integrity under impact. Both rail systems were made able to crack under impact, however some KeyMod rails lost integrity due to the fractures between slots.
Having trouble seeing the PDF in the frame above? Find it here; NSWC-Crane KeyMod vs M-LOK railsystem comparison