800 yard shots from a ww2 aircraft are very rare
Marion Eugene Carl once quoted over Guadalcanal "I dove to avoid a Zero, out of the corner of my eye I noticed a Zero attempting to turn around and get on the 6 of another Wildcat, I threw the Wildcat over and fired a burst at what I guessed was 800 to 1000 yards and the Zeke caught fire and trailed away".
David McCampbell is another to shoot down a Japanese plane on his "Ace in a Day" tirade at the Marianas Turkey Shoot with an 800+ yard shot on a Judy.
Wolfgang Treuding was a JG 51 pilot who did a head on attack with an IL-2 at 1200 yards+, dove away after his initial burst and watched the Il-2 crash; he assumed he killed the pilot for his 32nd victory?.
431st FS has a clear example of long range "gunnery" - they were due to escort B-24's departing from NadZab airstrip No 3 to attack Hollandia; the P-38s of the 431st were over head and were jumped by 15 Japanese fighters. 1st Lt. Frank Monk ordered the pilots to drop their drop tanks when he saw the enemy aircraft 1,000ft above them, diving from the right towards the Lightnings in front of him. The "Oscars" were heading for the tail section of "Green Flight" which was immediately in front of him, so Monk forced the Japanese pilots to turn away from their intended targets by breaking into them head on. One Ki-43 flew straight at him and from a range of 1200 yards 1st Lt. Monk open fired, the Ki-43 broke right with pieces of his canopy, engine and wing coming off. 2nd Lt. Horace "Bo" Reeves was a new pilot in the squadron flying on Monk's wing throughout the mission and saw the Ki-43 burst into Flames and disintegrated with the well aimed head on shot.
While true - not all attacks were done at such range, some times it was necessary. Major Jack Rittmayer was killed by a head on shot from a Ki-84 from around 800 yards; Rittmayer's P-38 was completely destroyed from the head on shot.
McCampbell used 1000 yard Shots to cause the Judy's to "Spread" apart, enabling him to pick them off one by one, most cases it was a head on shot; unlike Aces high where you just end up in a "tower" and can take off again, many cases men lost their lives.
So in the argument was it "uncommon" - there is no supporting evidence. Richard Bong once said he couldn't hit the side of a Barn from 20 feet away; often firing at targets well out of distance, same for Hans-Joachim Marseille. Marseille admitted his gunnery was horrible, shooting from targets beyond 800 yards; eventually he taught himself to be a marksmanship and it latter paid off. The guy who once fired at a Hurricane that was out of range in early 1940, eventually became ace in a day on 24th September 1941.