How often did WWII bomber gunners actually shoot?

But for those who came back . . .

A way to look at this question might be to compare action sorties to credited claims. I can’t discuss the question in terms of the USAAF gunners against their various adversaries. I can however discuss the question in terms of USN rear-seat gunners, the guy in the backseat of SBDs, SB2Cs, TBMs, and the turret and waist gunners in various patrol type aircraft. Gunners were what was referred in the vernacular as “free gunners”, that is one firing from a flexible mount arrangement, as opposed to a pilot who would generally be firing from a fixed mount, usually synchronized through the propeller, but, later in the war, with wing mounted guns as well. So, this will only address the free gunners, the back seaters (though, in truth, the same exercise could be made including the pilots or just for the pilots) and the turret and waist gunners of patrol aircraft.

First, though, a couple of things –

One, the USN clearly defined an action sortie. From US Naval Aviation Combat Statistics (1946) (page 8): “Number of planes taking off on a mission which eventuated in an attack on an enemy target or in aerial combat, or both. This basis of tabulation was the number of planes of one squadron taking off on the mission. If any of these planes had action, the entire squadron’s planes on the mission were counted as action sorties, including abortive planes, planes which reached the target but did not attack, and planes which escorted or patrolled but did not engage in combat. Thus if 16 VF took off as escort, 2 returned early, 2 engaged in combat, and 4 strafed, all 16 were counted as action sorties. Likewise, if 8 planes took off for CAP, and only 2 engaged in combat, all 8 were action sorties. On the other hand, if 8 VF took off for escort, and none engaged in any sort of attack or combat, then none were counted as action sorties, even though they reached the target, and even though the escorted bombers attacked the target. Likewise, CAP planes missions, none of whose planes engaged in combat were not counted as action sorties.” (https://www.history.navy.mil/content/dam/nhhc/research/histories/naval-aviation/aviation-monographs/nasc.pdf)

This is a convenient definition as it gives us the number of planes in actual action sorties which we can compare to gunner’s claims, knowing the number of gunners concerned per the aircraft type; usually one, sometimes two, gunners for single engine types. For two and four engine types (PBY, PB2Y, PB4Y, PBM, PV) perhaps, and I would say probably, more that one gunner fired on a given enemy aircraft. The USN tended to list credits for patrol plane types under the name of the patrol plane commander, but it is good to know that only pilots of the PV-2 had forward guns which were pilot controlled. And, just in case, we can cross check credits/claims against Frank Olynyk’s “USN Credits for the Destruction of Enemy Aircraft in Air-to-Air Combat World War 2” or even go back and check Aircraft Action Reports and eliminate single engine pilots and PV pilots from the equation.

Two, credited claims do not mean that a gunner actually fired on and actually shot down an approaching adversary, it just means that, yes, he did fire on approaching adversary and was credited with an actual shoot down, or probable shoot down, or inflicting damage on the enemy plane regardless of the actual historic outcome. All of which is totally different from actually, no question, shooting down an adversary.

The line between the two concepts makes using credited claims a good measure for this question . . . the question is not how many enemy planes were shot down by gunners, the question is how often a gunner actually had the opportunity, or occasion, to fire on an enemy plane. While certainly there were probably numerous occasions where a free gunner may have fired on an enemy plane without result or without making a claim, but looking at claims can give a good ballpark analysis.

Third, the below does not include the number of times a rear gunner or patrol plane gunner may have sprayed down a ground target or a vessel at sea. Since the OP appears to me to address firing one’s weapon at an enemy airplane, strafing does not appear to be an issue.

Not included here are the total number of flights versus the number of action sorties as the USN did not start keeping that figure until 1944. Overall though, on average, one can say for 1944 and 1945 there were 2.64 flights for every action sortie (388,530 total flights, 147,094 action sorties) with total flights defined as “Number of flights, for all purposes including combat and attack, reported for a calendar month by a squadron reporting action against the enemy (other than ASW) during the same month.” (USNACS, above page 8)

So, all that being said

In USN use, the Douglas SBD flew 11,331 action sorties over the course the war, flying from both carriers and from land bases. Credits to gunners were 41.5 enemy planes shot down, 5 probably shot down, and 13 damaged. Thus, rear gunners in SBDs probably fired on an enemy aircraft at least 60 times; or once every 189 action sorties.

In USN use, the Curtiss SB2C flew 19,140 action sorties, from both carriers and land based. Credits to gunners were 17 enemy planes shot down, 13 probably shot down and 13.5 damaged. Thus, the radio/gunners in SB2Cs probably fired on enemy aircraft at least 44 times; or once every 435 action sorties.

In USN use, the Grumman/Eastern TBF/TBM flew 38,854 action sorties, carrier and land based. Credits to turret and tunnel gunners were 44.7 shot down, 21 probably shot down, 45 damaged. The Avenger gunners probably fired their weapons at least 111 times; or once every 350 action sorties.

USN TBDs present a data skewing problem. There were but 182 combat sorties flown, the last being at the Battle of Midway. There of some 41 TBDs in action. Safe to say that the gunners in all those planes fired their weapons at least once. Of the other 141 action sorties, none of the records in my possession indicate an individual gunner firing on an enemy plane. So, gunners firing their weapons were at least 41 out of 182 sorties; or once every 4.4 sorties.

USN Consolidated PBYs flew 1,371 action sorties (many, many more flights, but only 1371 involving action against and enemy aircraft or ships. The same would apply to the other patrol type craft listed hereafter). Credits to PBY gunners for enemy aircraft were 18 shot down, 0 probably shot down, 0 damaged. The PBY gunners probably fired their weapons at least 18 times; or once every 76 action sorties.

USN Consolidated PB4Ys flew 3,624 action sorties. Credits to 313 shot down, 2 probably shot down, 1 damaged. The PB4Y gunners probably fired their weapons at least 316 times; or once every 11.5 action sorties.

USN Martin PBMs flew 506 action sorties. Credits to were 17 shot down, 0 probably shot down, 0 damaged. The PBM gunners probably fired their weapons at least 17 times; or once every 29.75 action sorties.

USN Consolidated PB2Ys flew 142 action sorties. Credits to were 8 shot down, 0 probably shot down, 0 damaged. The PB2Y gunners probably fired their weapons at enemy aircraft at least 8 times; or once every 17.75 action sorties.

USN Lockheed PVs flew 2,636 action sorties. Credits to were 9 shot down, 0 probably shot down, 0 damaged. Presuming all 9 were shot down by gunners, the PBM gunners probably fired their weapons at least 9 times; or once every 293 action sorties.

Personal opinion, there was probably considerably more firing going, but the above numbers are the ones which can be ascribed a name, date, place, and enemy aircraft type base upon Aircraft Action Reports.