Wild_Bill_Kelso
Senior Master Sergeant
- 3,231
- Mar 18, 2022
Maybe it's just as simple as recognizing the problem faced by planes like the Ju 88, Fiat Br 20 (used by the Japanese) and many others including Japanese types, in which gunners who either had other responsibilities or were in charge of multiple guns and often weren't ready to shoot at an enemy fighter in time. So they wanted a dedicated gunner for each gun (which may or may not have been a good solution to the problem, but may have been the answer the people writing the specs decided on).
Junk guns and heavy guns
One issue that comes up a lot is the ammunition capacity (or small magazine size) of defensive guns on Japanese planes, especially the 20mm cannon. This is interesting, but maybe could use some perspective. When a fighter is attacking a bomber, unless the fighter pilot is very inexperienced, it will be in a very rapid pass lasting at most a few seconds in which either aircraft is in range of the other. It's not like trench warfare in that sense. A defensive gunner will likely only have time for one or two very short bursts before the enemy fighter flashes by. Where ammunition capacity comes into play is where they are being repeatedly attacked and by multiple fighters either in formation or in series (a tactic developed by many nations during the war). But the 8th AF situation is somewhat unique and was not typical of most of the Theaters of the war in WW2.
Small ammunition capacity, lack of power traverse and limited numbers of guns are mitigated to some extent by bombers flying in formation so that multiple gunners can open fire on the enemy fighter(s) when it is making a pass. So even if they all have 15 round clips on those 20mm Ho-1, or 60 rounds on the Type 99, an enemy fighter would potentially be targeted with multiple bursts from the heavy guns of 3, 6, 9 or 12 aircraft as they make their approach.
Sr6 has made a lot out of the 'junk guns' of the Japanese. There is some truth to that. They had rather poor small arms and crew served infantry weapons as well, but they were able to make them work well enough to sweep aside British and American forces in Malaya and the Philippines, and to prove quite a challenge in many subsequent land battles in China and in various Pacific Islands. I think to a point quality of the firearms matters but a .30 caliber rifle or machine gun is still pretty lethal, and a 12.7 or 20mm gun definitely is.
So I don't believe Japanese defensive gunners posed a trivial threat, particularly the heavier guns but not just them. Even very successful units like the AVG routinely took losses to defensive gunners of IJN bombers, including relatively flimsy and poorly defended aircraft like the Ki-21. Gunners on the G3M, G4M and Ki-49 were somewhat feared due to their 20mm guns and allied pilots took steps, like attacking from below or from the front, to avoid them. The Japanese pilots were particularly well known for their tight and precise formation flying - this was in part done (and emphasized in their training) to increase the defensive firepower from their guns. If you came up slowly behind a formation of G3Ms or G4Ms or Ki-49s in an Allied fighter, you stood a fairly good chance of being hit and even one shell from the 20mm could be devastating. The later Ki-49s actually had multiple 12.7mm Ho-103s replacing the 7.7mm as well.
Turrets
Once again we tend to look at this issue almost exclusively from an 8th AF point of view, and maybe a little bit from the British perspective. But in the Pacific (and the Med) defensive guns on bombers did make a difference and did indeed cause problems for fighter pilots. The US made planes like B-25, B-26, Baltimore, B-24 and B-17, and even the Hudson, which had power turrets, did prove to be a problem for Axis fighters. They had to develop special tactics to attack them, and in the Pacific it was not at all unusual for these bomber types to go on raids without escorts. They still needed escorts in the Med, and this was the role of the P-40 for light and medium bombers and the P-38 for the heavy bomber, both of which had somewhat extended range compared to the German and Italian types, and this conferred an operational advantage, allowing the Allied planners to make strikes in a wider array of target areas which were difficult to predict and defend. The Japanese had a similar advantage in the Pacific and China / Burma / India, as Just Schmidt pointed out, quite capable fighters were available which could in fact escort the bombers, further than any of the US types except maybe the P-38.
Speed
I do think gun turrets and heavy defensive guns mattered, but so did speed, even where very fast fighters were available. In the Med, the Boston / A-20 / DB-7, the Martin 167 Maryland, and Martin 187 Baltimore all proved quite successful and took relatively low losses in large part due to their speed. The speed was largely used for egress from the target area, or to evade and abort if they were intercepted by fighters early. Faster speed means that there is a shorter window for the fighter to intercept. It makes it harder for AAA gunners to target the bombers. Yes some fighters were available that could climb 4,000 feet per minute and fly 370-400 mph, but to do so they burned through fuel at a rate which quickly left them depleted, and with enemy fighters in the area they may need that fuel to defend themselves.
Now of course, once you are later in the war where the Allies have air superiority and there are relatively few Axis fighters still around, interceptors have a little more leeway, needless to say.
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