Fallout Weapons Guide: Heavy Weapons
by Mazca

Minigun
Powerful but rather useless, the Minigun is a bit of a waste of space in my opinion. It can only fire in a 30-shot burst mode which doesn't do as much damage as it should - no more than 1.5x that of an assault rifle burst. Hence, it is inflexible, totally eats ammo and is very heavy indeed - leave it.

Flamethrower
The flamethrower is good for surprise attacks - walk up behind someone and burn 'em up before they notice you. However, it is very short ranged (only 2 hexes) and it's ammo is very heavy indeed. If you need some short-range firepower then buy it, but you'll probably want to sell it again once you're finished.

Rocket Launcher
Probably the most powerful weapon in the game, it is also rather useless. The launcher costs nearly 15,000 caps and the rockets are very expensive and rare too. You need a very high Big Guns rating to use it properly - otherwise you will waste huge amounts of costly ammunition. It's sometimes useful against very powerful enemies like the Mother Deathclaw or Master, but generally a plasma rifle is a better bet, as well as being a lot cheaper.

Note: all of these guns use your 'Big Guns' skill. As you may have noticed, I don't think much of any of them - Hence, if you are following my advice, don't bother with the Big Guns skill at all, concentrating on Small Guns and, later, energy weapons.