In TF2, I was wondering how, as a soldier with a Beggar's Bazooka, you would you kill a scout effectively. Since it takes such a long time to load all three rockets, the scout usually has already killed you by the time you'd be ready to fire. Any tips on how approach this?
Most of the time, you should let your teammates kill the scout while you reload. The Beggars' Bazooka is not a weapon you should be roaming solo with - its 1v1 and jumping abilities are somewhat unreliable due to the whole loading mechanic and reduced accuracy, and the recent change has reduced its jumping abilities (overload jumping comes with a penalty). In other words, if you ever find yourself alone with an unloaded Beggars' Bazooka against a scout, something went wrong.
If you do find yourself in that situation, as has been stated shotgun is probably your best bet. Another alternative is trying to use single rocket jumps to run away.
If you are really trying to roam with the Bazooka however, you probably have Gunboats on, in which case jumping away is probably your only option.
A good beggars loadout is: Beggar's Bazooka, Reserve Shooter, and the Escape Plan.
The Bazooka is useful with groups of enemies. When in hostile territory, start loading it up when rounding corners, as you could then ambush quick enemies which would normally take you by surprise.
The Reserve Shooter is good for taking out enemies that are up close. Because of its swap speed, you can easily switch to it to shoot a scout, then switch back.
The Escape Plan is designed for, well, escaping. If you are dying, use the weapon swap speed from the Reserve shooter, switch to the Escape Plan, then run away. Or, you can use it to get around, dodging the scout, then swap to Reserve to finish him.
Beggar's Bazooka is a terrible weapon when you need firepower immediately and critically - you should use a good secondary when you're weilding it. Either a Shotgun, which provides good close-range burst damage and modest mid-range damage, or the Bison, which will provide better long-range options and modest but consistent damage. Choose depending on what you need.
As for handling the Beggar's Bazooka itself, it's a very situational weapon. Don't treat it like a "special" rocket launcher, because it's not nearly as versatile, and much less reliable.
What it can be very good at is sudden, wide-burst area denial. This is best utilized at choke points, narrow corridors, or when you have time to prepare for your enemy's approach. The benefit of the Beggar's Bazooka is that it fires many rockets at once, over a wide area. You should be using it when you know you're about to encounter a large number of enemies, or when you know you'll be able to funnel your foes into narrow spaces.
If you know that's not going to happen, you should either move to another area of the map, or consider switching off Beggar's Bazooka altogether. Note that it works better on Defense, regardless of the map or situation, because you know that you'll have a narrow area guaranteed to have enemies gathered together tightly all at once.
Beggar's Bazooka is very tricky to handle. Not only does it take extra time to fire at first, but the backfire gets extremely annoying.
I recommend that you stick to this:
Beggar's Bazooka, Buff Banner, and the Escape Plan.
As mentioned by others, the Escape Plan is a good getaway, and if things get tough, it can be used as an insta-kill suicide taunt.
The Buff Banner helps a lot when you rack up the kills.
Personally, you should stick with this layout for Mann vs. Machine. It's one of the best Soldier tactics.