So the P-51 should have a converg of

[BaldEagl]

MtnMan, with LOD distances you may land hits but be too far to see the hit sprites.

Nope.  I had at least 4-5 1000 yard kills this camp with .50 cals and could see the hit sprites every time.  You do have to "pour it on" though.

[Furball]

Staggered convergence just doesn't work as well in AHII

I agree.  The one exception being the 262.  I put one set of guns far out and one pretty close in to get a "shotgun" effect, seems to work pretty well in the jet where concentrated firepower is not a necessity.  Can't remember the distances i use.

[SmokinLoon]

I have all of my air to air aircraft with wing mounted weapons, regardless of caliber, converging at 350.  The only exceptions are those planes I go bomber hunting with, they are set to 650. 

I have all of the aircraft with center mounted weapons I will stretch them all the way out to 650 (Mossi/P38/109).  If I have a "combo" aircraft with both center and wing mounted guns the setting is at 350. 

[mtnman]

MtnMan, with LOD distances you may land hits but be too far to see the hit sprites.

I was measuring using the .target, and moving it in closer after I shot at it to check for "holes".  LOD would not be a factor, from what I can tell.  The bullets didn't get to the target at ranges greater than I mentioned.  And they didn't go under it either.  Lots of hits at 1100 yds, at 7500ft, a few at 1110, but none at 1120.  I was flying on auto-level, with the sight in the center of the bullseye, and zoomed all the way in.  I simply moved the target in and out by typing...