STANAG magazine
In autumn 2007 the XM8 was compared to other firearms in a 'dust test'. The competition was based on two previous tests that were conducted in summer 2006 and summer 2007 before the latest test in the autumn of 2007. In the summer 2007 test, M16 rifles and M4 carbines recorded a total of 307 stoppages. In the autumn 2007 test, the XM8 recorded only 127 stoppages in 60,000 total rounds while the M4 carbine had 882. The FN SCAR had 226 stoppages and the HK416 had 233. The difference between the XM8, HK416, and FN SCAR was not statistically significant when correcting for the less reliable STANAG magazine. However, the discrepancy of 575 stoppages between the summer and autumn 2007 tests of the M4 had officials looking into possible causes for the change such as different officials, seasons, and inadequate sample pool size but have stated that the conditions of the test were ostensibly the same.