Explosives can be very powerful and I've read some online guides for making a build based around them, but I'm not sure if they would be practical. The risk for friendly fire is very high against your allies, neutral npcs, and yourself. Demolition Expert, Hit The Deck, Splash Damage, Heave Ho, Mad Bomber, and Nuka Chemist are among the perks listed that would be useful. Nuka Chemist allows for crafting infinite Nuka Grenades with Mad Bomber, which also unlocks recipes for craftable grenades and mines.

There are a lot of powerful explosive weapons. Mercy, Annabelle, Red Glare, Fat Man, Nuka Grenades, Plasma Grenades, 25mm APW, Thump-Thump, Grenade Launcher, and Holy Hand Grenades. The Grunt perk affects a few explosive weapons giving them a damage boost that stacks with Demolition Expert.

Of course, all that weight of the explosives, missiles, grenades, mini-nukes, and rockets can really weigh you down, even with Strong Back, Pack Rat, and Burden To Bear.

From what I've seen on Youtube, some of the weapons listed above and certain ammo types are better at killing off deathclaws than others. And I'm sure that going through the Battle of Hoover Dam would be next to impossible to win without heavy casualties on both sides of the conflict. And in tight corridors...well you get the idea.

So I've got four explosive builds planned: one that uses the Grunt perk, one that uses thrown grenades, another using launched grenades, and another using rockets and missiles. But I'm not sure if any of them are practical enough to take me through the whole game.

Has anyone ever tried an Explosives only build? Is such a build possible? Or are Explosives better used as a secondary attack?

I haven't tried it as a primary skill, but my main concern is availability. At the start you'd probably want to go immediately kill a bunch of Powder Gangers for their dynamite. Adamantium Skeleton would be another worthwhile perk.

Some DLC areas could be a problem. Honest Hearts limits what you can bring in with you. Dead Money takes your whole inventory away for the duration. You could scrape together some grenades from disarming traps but it won't be much. Old World Blues has a lot of mines to salvage, especially on top of the pipelines.

In other words, no? It's better used as a secondary combat skill for non-critical builds?

That's my instinct, but feel free to try it.

I'm often annoyed at how bouncy the grenades are, but throwing them in VATS helps land them directly on an enemy.