Here are some of the tricks I've noticed for forcing overshoot and how I counter them:
1) Quick E Bleed Skid - Various planes have large rudders (La5, P-51 and F4U) which allow them to bleed ALOT of speed in a very short time. I can take a 51 from 300+ down to 150 in less than 10 seconds (side note: is this realistic??). Anyway the trick is to use a combination of your roll rate (to avoid the shot...kinda like a scissors) and the E Bleed to avoid the shot on an incoming bogie so that he blows past and then hope for a snapshot. The problem with this move is that most planes accellerate very slowly (except the La5). If you dont get the snapshot, yer dead meat.
The safest way to counter it is to get yourself a little verticle separation from the target. Chop throttle a little, pull up and climb in a slightly banked turn to put yourself about 30 degrees off the tail. Reacquire the bandit and roll back into him. This E bleed is usually only good 1 or 2 times before the enemy's E is depleted.
I HARDLY EVER use this move since yer hoping the guy chasing you doesnt use good E management. This move puts the skidder at a severe disadvantage.
2) Rolling scissors. This is a move that works GREAT. Basically its started with a high G low yoyo to one side starting when the bogie is about 1.6 off your tail. Roll about 190-200 degrees and begin a high G bank back into your attacker. The key is to pull hard enough to enter a partial blackout but not so hard that you lose sight of the bogie. Keep the bogie centered in the screen during the first part of the move.
What you do next depends on what the bogie does. If he pulls up, stop your move, roll level and try to pick up more speed to either gain separation or to get ready to do this again. If the attacker continues to force the shot, continue your roll around and reacquire the target in your up/forward-up views. Ease off the stick a bit and use lag pursuit to follow the bogie. He is probably just now passing you. At this point, you may be able to roll around and follow his plane in lag pursuit to build up E while hes fighting a blackout and pulling max-Gs. If the speed differential is not too great at this point, you may have a snapshot. If he gains separation, you have whittled the E margin down considerably. Set up for his next attempt.
3) Verticle Overshoot - This move works well when you are in a superior climbing plane to your attacker. Basically its similar to the previous move but requires you to have enough speed to go into a max-G climbing turn once the enemy is in guns range (1.6 or less).
As the bogie dives on your 6, you pull up and into a high G yoyo again trying to keep sight of the bogie. You may want to roll a bit as you come around so that you dont give the enemy a good snapshot. As the attacker passes by, roll your lift vector into him and set up for a snapshot.
The best guns defense is never to require it and when you do, to use the advantages of your plane against his. If you are in a faster plane, use option 2 to whittle down the E differential to allow yourself to gain separation. If you are in a better climbing plane, you can use either 2 or 3 to deny the shot and set up the snapshot.
-Ding