1. We have shit loads of them
not necessarily. Now, under the current dispensation, the elite forces atleast have access to any kind of weapon they want. I'm sure that avoiding changing a primary weapon to get just a slight edge in combat, when you CAN get the job done with the present one is far more prudent than changing the primary weapon and incurring heavy costs first of all in training all troopers proficiently on them, and secondly of introducing a lead time till the entire force is proficient on the new one. Changing the standard weapon for the unit is a decision the top leadership has to make, and they have to take these factors into account, irrespective of the gear demands at the trooper levels.
The modern threat perception has changed even within HRT the 9mm cannot penetrate body armour
I mentioned the same in my post, that short of penetrating body armour, the 9mm Parabellum has sufficient stopping power, especially when combined with Mozambique drill type shooting patterns, two to centre mass, one to the head, or even double taps.
As someone stated the .45 calibre is already making inroads
.45 cal is no better at penetrating body armour than 9mm.
PS you mentioned 50ms accuracy . Almost no built up CQB happens within 50ms it's usually within 10-20 feet on average.
If you are looking at 50 mtrs then you are in open ground and the MP5 starts getting pretty useless after the first 50mts
yeah that's what I said. CQB happens well within 50 mtrs especially in the kind of CQB SAG is supposed to do. So an Mp5 is well suited for that. At 10-20 ft, an Mp5 will fire pretty much at the exact spot at which it aimed, without any bullet drop at all.
Controllability in rapid fire and maneuverability in tight quarters is also a factor to be taken into account for a CQB specialised force.
Like I said, if transition is to happen then why stop at SIG, go the long haul and go for HK416 with 10 inch barrels. Its what ST6 use for CQB along with Mp7.
OR better still, get the X95 which affords all the benefits of the armor penetration of 5.56mm, along with the tight controllability of a bullpup.
