The M1 Carbine is the standard by which all PDWs are measured.

[NugginFutz]

Still don't see references to any bonafide testing - the wiki cited is only stating a terminal figure which, in the linked citations, was based only on tables and calculations, not testing. While I do not possess the hard copy book cited, the links I could follow never mentioned formal testing of the Grendel. The only testing I could locate was mention of SOCOM field tests, in 2012 - no results mentioned other than some of the soldiers preferring the 6.5 for its better accuracy at ranges beyond 500 yards. Unfortunately, this was an unsourced statement, with no means to validate even that reference.

As an aside, SNS, this is the reason none of my professors ever accepted Wikipedia citations.