Requirements for Replacement of Currently Issued 5.56 M-855 and 7.62 M-80.

[stanc]

I can see a quick transition to an under the shoulder or back carry for everyday duties.

There was a shoulder holster made for the MP9's predecessor, the Steyr TMP. One might think that shoulder or chest carry could also be made for the MP9.

Here's a Portuguese soldier w/MP9 on leg rig in Afghanistan.