MrGunsnGear looks at the magazine adopted by the USMC
If you want to see the test results in the video, TFB has it.
http://www.thefirearmblog.com/blog/2017/07/21/us-armys-new-magazine-failure-usmc-test-enhanced-performance-magazine-shows-performed-worse-predecessor-pmag/
From: MrGunsnGear, The Firearm Blog
