I am a retired senior Infantry NCO. My last assignment oin active duty in 1999 was as the 1st Sgt of a light Infantry Company. I don't post here often because i don't like to get embrouiled in a flame war. When I do post, i try to stay away from stating a fact or cdescribing a situation wuithout citing a source to valid what I write. please note that i have done that in this post.
here are some very basic facts about an infantry unit. There is a Table of Organization and Equipment (TOE)for every unit in the Army. There sometines is a modified Table of Oirganization and Equipment (MTOE)
For a typical light infantry company (by light Infantry it means they are not mechanized or airborne) that is authorized 136 people, each person is described to include his rank and title, his weapon and even his night vision or optic. Here is a link to the standard MTOE of an Infantry unit in the 101st Airborne (Air Assault) Division:
http://www.fas.org/man/dod-101/army/unit/toe/07017L000.htm
The ONLY people in a typical Infantry company that are authorized a pistol are the six machine gunners, the three mortar gunners, the Company Commander and the Supply Sgt. Everyone else is issued a rifle.
There are only a total of 11 pistols in an entire infantry company.
The M9 is a very old pistol in service and in fact, it is a very old design (1951) and that's a copy of an even older design (1934).
It is a big gun. Many of the people who are assigned a pistol as a primary weapon (flight crews, MPs, CID, medics. etc) are small such as women. The M9 is not a usr friendly weapon for anyone with small hands.
The new proposal for bids concerning a new pistol does not describe a specific caliber other than it is required to equal a certain standard in specific situations, for instance range. The request for proposal does require that a pistol submitted has to be modular in design, that is, it has toi be able to be adapted at the organization level (the lowest level of maintenance) to be mission and user specific. In plain language that means that the pistol has to be able to be adaptable for concealed carry (replacing the M11 which fills that role now) and it also has to be adaptable for the individual user. That means it be able to be re-sized to fit the operator's hands and ambidextrous.
So, the new pistol has to be lethal within certain parameters and it also has to be size adaptable.
There has been a lot of disinformation poull out about this on many forums and blogs. As I stated, I always try to provide a source document so here is a link to the actual request for proposal and it describes the requirements of that the military wants in a new pistol:
https://www.fbo.gov/index?s=opportunity&mode=form&tab=core&id=fd2662aa6580151c9fdc7dcf0f0481e5
I am really not interested in getting involved in some internet chest beating war. I don't have a dog in this fight, I am presenting (and citing) facts concerning where the military is headed with a pistol.
BTW, the Marines are issuing those M1911 pistols to their Special Operations folks not to the line snuffies. Their Special Operations folks have been carrying a 1911 pistol for decades, mainly rebuilt M1911s many of them built for my Father's generation. They just can't keep the old guns going anymore they were played out.