IN THE HANGAR:
(a) set your convergence for all 4 guns to 350. This will give you an effective cone of fire out to d700. You can set it farther if you want, if you anticipate strafing ground targets or chasing fast planes or engaging bomber with tailgunners. I've hit with .50 cals out to d1.0, so you could get away with setting convergence out to the max of 600 (I think that's the max that's available), but realistically, at that distance, the target will appear in your gunsight so small that you may have a hard time seeing it. You'll also have some bullet drop-off due to energy loss and with four .50 calibre guns firing, you'll need for a majority of them to hit, so as you set your calibration farther out, you can expect to have to stay on the target longer. Because there are only 4 guns firing, I set my convergence to a single point for maximum effectiveness.
(b) if you're planning an out-and-back mission between two front-line bases, 50% will give you a good range. It will fill both wing tanks to just over their 50% capacity and leave the auxilary fuselage tank dry. I've found that I run out of gas before I run out of ammo, so I've started carrying 75% gas, which fills both wing tanks to capacity and gives you a bit of gas in the auxillary tank for climb-out, which frees up the wing racks for bombs. With this load-out, you'll be a bit heavy when you launch so it may be a good idea to start from a base back, or if you lauch from a front-line base then you should head away from the front for a bit before turning and heading for the action. Some guys go with 50% and bring a wing tank or two for climb-out, which allows them to lighten their fuel load in case they get jumped by bandits on their way to the lines. If you're launching from a base back, the difference becomes moot, as either way you'll be at 50% gas - either by dropping your wing tanks before you get to the front lines or burning off your auxillary tank.
(c) I don't carry rockets in the P-51B. The tubes, once empty, aren't worth the drag penalty. Instead, if I want to carry ground ordinance "just in case", I'll load up the 500 pound bombs. That way, if I find trouble on the way I can pickle the ordinance and have a clean airframe.
IN THE AIR
(a) I sometimes WEP right off the runway until the engine temperature needle pegs in the middle of the yellow zone. WEP is most effective up to around 15k and then hits a dead spot between 15k and 20k. If you're chasing bombers, the WEP will help around 23k and up, but I rarely get that high because from that alt I'll never see the bandits cruising at the more common altitude of 10k below me. Some guys like to climb out on normal power and save their WEP for fighting, but I've never run out of WEP in the MA and rarely have to use it in a fight unless its gone on for a bit and we're both running out of airspeed. Usually I'll only use WEP if I'm going into a nose-high turn and need to hold my speed. A B-stang isn't going to out-climb too many opponents, WEP or not, and most fights tend to fairly brief encounters before more aircraft arrive to determine the outcome. Burn the WEP on launch if you're impatient, or hold it if you'd rather take a bit longer to climb out, its up to you and what you feel more comfortable doing.
(b) Set your views. The B-stang of WW2 came with two options - the standard caged canopy and the Spitfire-esque Malcolm hood. Unfortunately, in Aces High, the B-stang only comes with the factory canopy. This causes some blind spots from the pilot's seat so make sure you set up your views with overlapping fields of vision. You also have a large blindspot dead behind you, so keep this in mind when you set your views, and get in the habit of jinking the plane from time to time to clear your baffles. If you fly the B-stang for any amount of time, you'll develop a healthy sense of paranoia.
(c) I usually cruise at 20k in the B stang for two reasons. First, this is the alt that the other Mustangs are usually at, along with the P-47s, Typhoons, Spitfires, and most of the Luftwaffe fighters. At that alt, the Mustang's speed is discernable, outpacing most other fighters found in the MA, most of the time.
(d) If the target is below, make sure you mind your airspeed in the attack dive. The B-stang can be a handful as the airspeed increases, almost as bad as a P-38 or 109. I usually drop a notch of flaps and cut throttle if I go into a sharp dive, then listen for the sound of the flaps retracting to let me know when I'm getting a bit on the slick side. If you let your speed get out of hand, bad things can happen, like becoming a green meteor on its way to becoming a crater. In a gentle dive, such as when chasing a Typhoon, LA-7 or another Mustang, don't be too concerned if the cockpit starts vibrating. You'll still have control, but don't make any sharp pulls on the joystick or you may rip off your wings (I've done that in a D-stang, but not in the B-stang). Chances are, if you're going that fast, the other guy won't be doing much turning either. Just be mindful of your pitch and the proximity to the ground or you could end up either face-planting or, if you do manage to get the nose up, mushing the belly into the dirt.
(e) 109 pilots usually adapt to flying the B-stang fairly quickly, mostly because they're used to heavy controls at high speeds and the effects of compression on the airplane. The B-stang doesn't suffer nearly as bad as a G-10 in this respect and can go faster before controls become excessively heavy, but remember that you don't have a nose cannon and that your convergence is at d350 instead of infinity. If you're a 109 pilot, you'll also have to remember that you may not necessarily be able to climb away from the fight. The Mustang will zoom up pretty well, but only if you've zoomed down first to get some energy going.
(f) Remember those two 500 pound bombs on your wings? Ok, so you've decided to attack something on the ground. In the B-stang, you'll have to release the bombs a bit higher in a dive than you would in something like a P-38 or Hurricane, mostly because your downhill accelleration will be pretty quick unless you've dropped all your flaps (which isn't something I would recommend doing if there are enemy aircraft in the area) and you may have trouble recovering from the dive due to the high speed. Your bombs aren't strong enough to knock out a hangar unless its light, but cities and ground vehicles are fair game. Your four .50cals are better suited to fighting enemy airplanes and aren't really the best choice for ground strafing. So if you've used your bombs, go ahead and climb for altitude and wait for the enemy response to your raid. The Mustang has pretty good range so you can loiter over the battle area for awhile and let the action come to you, or start heading towards the next-nearest enemy base and catch them as they're climbing up.
