Israel has developed a hand grenade that is much less likely to explode when hit by a bullet. This was in response to an incident two years ago, when an Israeli army officer along with a nearby sergeant died when a Palestinian bullet hit and detonated a grenade the officer was carrying.
This had long been a risk when carrying grenades but rarely was a grenade set off accidently by a stray bullet, at least while the grenade was being carried by a soldier. But the Israeli Defense Forces Munitions Branch found that a small modification of the grenade design would make such accidental detonations almost impossible. The grenades still look and operate the same way and all new ones will be manufactured with the new safety feature. Eventually, in 10-15 years, all the older style grenades will be gone (used in training or combat or withdrawn because of age) and only the new, more stable models, will remain.