I see lots of good tips and points here. Hag, hobble, eagles just to mention a few. Try about 400 for convergence, I regularly hit at 800 to 1000 with that setting if a plane is hung or not moving much. Horble witnessed it on a 109k4 I got the other night. Unloading gs in a crossing shot is the biggest factor, let's consider this. If you can pull lead enough to hit the nmy your spraying bullets over a wide arc. However if you can back off on the gs fire to 1 point and the nmy plane flies through this your gonna get a kill with 8 50s and land nearly every round. I see lots of 50 flyers using the spray and pray method, you simply can't do that in cannon birds and get more than 1 kill. I like the burst and lead more than you think. I find I cut many tails off when in a turn fight. Slightly more lead would land an instant kill on the pilot. 50s are great for this! Lead more, 400 yards ( shoot at your convergence too) patience! Short burst , less gs . Hly you already dodge bullets in that jug like the matrix, these tips and practice implementing them will help.
I have found many times myself I'll be down to 100 20mm or less and start really focusing and holding till I have good clean kill shots and get 3 or 4 more kills.. where prior I might only have 1 or 2 on 250 plus rounds expended. FOMO is real too. Patience BigDawg!