In what should be a surprise to no onw, the Israeli Defense Forces have adopted the MTAR-21 Micro-Tavor as their weapon of choice.

Once again, it allows us to look at why the M4/M16 needs to be replaced in US service.

In addition to its gas tube operation requesting excessive cleaning, it’s just too damn long:

	Overall Length	Barrel Length
TAR-21	725 mm (28.5 in)	460 mm (18.1 in)
MTAR-21	590 mm (23.2 in)	330 mm (13.0 in)
M16	1000mm (39.5 in)	508 mm (20 in)
M4	838 mm (33 in) (stock extended) 757 mm (29.8 in) (stock retracted)	368 mm (14.5 in)

While it’s clear that the both MTAR-21 and the M4 having 13½ and 14 inch barrels respectively, will have lethality problems at range. The 5.56 mm round is light and uses high velocity to carry to provide lethality, but the M4 is much more extensively used, because for any urban situation, the M-16 at 1m long is simply unmanagable, while the TAR-21, the normal rifle for the IDF with an 18 inch barrel is shorter than the M4.

The additional 4 inches of barrel also get the mussel velocity high enough to avoid the lethality issues at 100 m or so.

That is an very small package though.