At the moment, I'm seeing on average three grenades doing what one should do on early level bipedal enemies (no Demolition Expert Perk). One should be enough to kill or make combat ineffective (which is really a kill in this game) any unarmored enemy within 5 meters of the detonation (unarmored would equate to anything less than Combat Armor). 40mm isn't exactly common, so I see no reason why it's not as powerful as it "should" be compared to other weapons.

I loathe to see what a single grenade will do to a Deathclaw (it should be a one-hit-kill on a torso hit if we allow the Anti-Materiel Rifle a one-hit-kill with a sneak critical head shot, which is an easy shot).

It isn't a very powerful explosive weapon. Good when you're an early level player, but higher up move towards the Missle Launcher. I never did like explosives just for that reason.

One of my regrets about this game is that explosives are very inconsistent. Sometimes they explode and there is no damage at all; sometimes they work pretty damned good. I've bounced 40s off a deathclaw's chest and they have been unscathed while their companions have been blown to bits. It's almost as if there is a safe zone in the center of the blast.
The one thing I have learned is that explosives tend to work better out of VATS; I don't know if this is 'true', but it's been my experience.

Explosives in F:NV are highly bleh. Most don't do as much damage as they really ought to, and the ones that do (grenade machine gun, missile launcher) are stupidly heavy in comparison to any alternative. They become kind of okay if you take all 3 ranks of Demo Expert, because then your 40mm launcher might actually kill something, but.... really, Explosives is good for laying mines and that's about it.

On the other hand, mines are pretty good and you'll be picking up tons of the things. And if you use VATS to throw hand grenades and dynamite and you make the roll, it will land right at their feet and explode instantly. No more bouncing and fuse delay.

Grenade. Machinegun. Nuff said very usefull actually

Only way 40mm grenades are useful is with Mercy:D

There's a thread called http://www.gamesas.com/index.php?/topic/1153989-fixing-explosives/page__p__16888880__hl__explosives%26%2333%3B__fromsearch__1#entry16888880 that addresses a lot of this.
I've been informed that the 40's don't do direct damage. That's just weird.
Thanks to the person who pointed this out.

On my first visit to the quarry I picked up the fatman and landed a mini nuke right beside the female deathclaw with all the babies, killed all but one of the babies and only wounded the matriarch.

Since that happen I haven't used explosives unless they are modded. Un-modded they prove far too unreliable. (Mini nuke blast really should be instant death too all that are right beside the explosion).

In fact a Bottlecap Mine does more damage than a mini-nuke. Yup, cherry bombs are the most deadliest explosive devised by man :lmao:

You must be a professional thrower, because I can't use explosives without vats

Just an overenthusiastic amateur.
Dem tings blows up reeaall goood.

You can add the Missile Launcher to the list. Seriously, a direct hit on a Deathclaw and you only have about 50% or less damage done? Granted, it often cripples the legs if you aim at such, which makes them move slow, but it's silly that a missile (see: a massive "bullet" filled with explosives that's eons more powerful than a .50 BMG round) can't take one down with a single torso hit. Splash damage seems fine (explosives do drop off in power pretty quickly, especially with man portable HE stuff), but it needs a direct hit number greater than the AMR also, the same with 40mm rounds.

Using the Fat Man with all the explosive Perks makes the Easter Bunny cry. The Fat Man was barely adequate in Fallout 3 for what it is.

All of you seems to forgot AOE damage is calculated from the victims foot; for maximum damage, explosive have to denote right next to their feet.

I think the easiest "fix" for explosive would be increase limb cripple multiplier so it destroyer mobs limb relatively easy.