There are currently more M4 rifles in use in the IDF then any other rifle.
The M4's (and M16A1, M16A3, and various other M16 variants) have been in constant use by the IDF since the 1970's.
My M16A1 is so old that it rattles loudly. But it still shoots great.
The IDF uses the M4 for the majority of it's rifle tasks, from sentry duty, to specialized Urban Warfare an everything in between. Anti Terror squads, marksmen, infantry, combat engineers, all carry the M4 in various configurations, with all kinds of accessories.
Chrome lined barrels, scopes of all kinds, and even M203 grenade launchers are in use by the IDF on their M4's.
Training with the M4
Nahal Hareidi Infantry Unit with lots of footage of the M4 in action. You can see how it's used while manning checkpoints, arresting terrorists,with various scopes, bi pods, and other accessories.
M4 with detachable carrying handle
M4 carbine with M203 40mm grenade launcher
M4 with forward mounted handgrip and night vision sight
M4 with M203 40mm grenade launcher, note the retaining cord on the dual magazine, and attached rifle sling.
M4 with 90 degree angle mounted magazine (in holder) to keep the magazine handy, and attached rifle sling.