How many rounds of ammunition could the various F2A types carry?

[FulmenTheFinn]

I've tried e-mailing, DM'ing, or otherwise messaging a number of people acquainted with the aircraft, as well as the Cradle of Aviation Museum about this, but none have replied to me, so I'm asking here now:

How many rounds of ammunition could the various F2A "Brewster Buffalo" type aircraft carry, including export models? I'm not confident in the figures typically found online. See below.

First it's important to include what I've discovered thus far. This is from my message to the Cradle of Aviation Museum, quote begins:

1) For the F2A-1-based Model 239 the Brewster Aeronautical Corporation (henceforth shall be abbreviated "BAC") Report No. 350 "Detail Specification for Model 239 Airplane Class VF" mentions the .50 cals, one in the fuselage and one on each side of the wing, carried 200 rounds each and the .30 cal in the fuselage 600 rounds, so 600 x .50 and 600 x .30 in total per aircraft.

2) The part and equipment lists for the Brewster Model 239 in the Finnish National Archives from 23 May 1940 and 30 May 1942 list the following:

"2 pcs cartridge belt boxes in the wings for 220 cartridges
[...]
1 pc cartridge belt box in the fuselage for 220 cartridges
[...]
1 pc cartridge belt box in the fuselage for 600 cartridges"

So a total of 660 x .50 and 600 x .30 cal rounds per aircraft.

The above differs from the figures in BAC report no. 350 by 20 rounds per .50 cal. Presumably there was spare room the Finns used up by squeezing a few more rounds in. All good so far. However now it starts getting trickier:

3) According to Finnish aviation historian Jukka Raunio the boxes for the wing .50 cals could hold 400 rounds each. [...] I suspect his figure may be a result of misreading pp. 28-29 in BAC report no. 350, but let's move on.

4) Kari Stenman in his book "Brewster Model 239 Suomen Ilmavoimissa [Brewster Model 239 in the Finnish Air Force]" mentions that the ammo belts on the wing .50s could carry a whopping 800 rounds, in other words a total of 1,600 x .50 cal rounds in the two wing machine guns alone!

Then according to Kari Stenman's and Andrew Thomas's "Brewster F2A Buffalo Aces of World War 2", pp. 23-24, on 4 March 1942 Finnish ace pilot Lauri Nissinen reported to have expended 1,500 x .50 cal and 1,000 x .30 cal rounds in a single attack with the Brewster Model 239. This amount of ammunition carried far exceeds the figures given above.

I recently found a 1967 drawing of an F2A-3 which is "based on VF-2 average operational figures" (VF-2 flew both the F2A-2 and F2A-3 - I don't know if they flew the F2A-1, but that's neither here nor there) and was drawn by the assistance of F2A pilots from said unit. The drawing mentions the two fuselage .50 cals in the F2A-3 as having 500 rounds each, and the two wing .50 cals as having 800 rounds each, so 2,600 rounds .50 cal in total. This drawing can be found on Google in a file called "Buffalo-Modellistica-2023.pdf".

Also, the book "America's Hundred Thousand" mentions that the F2A-3 could carry more ammunition than its predecessor types, but doesn't elaborate on this claim in any way.

Quote ends.

To clarify, I'm interested in the maximum amount of .50 cal, and when present, .30 cal ammunition the aircraft's various types could carry.

Any input with all of the above in mind is appreciated, thank you.

 

[Greyman]

A thorough examination of W.8133 (339E) by the A&AEE gives 250 rounds for each fuselage .5-inch and 450 rounds for each wing .5-inch.

This is for the ammunition tanks only, and doesn't count any extra belt leading from the tank to the gun.

MAP data sheet for the 339E gives 250 rounds per gun for the fuselage .5s and 500 rounds per gun for the wing .5s (perhaps indicating the extra belt I alluded to?)
MAP data sheet for the 339B gives 160 rounds per gun for the fuselage .5s and 300 rounds per gun for the wing .303s

 

[FulmenTheFinn]

A thorough examination of W.8133 (339E) by the A&AEE gives 250 rounds for each fuselage .5-inch and 450 rounds for each wing .5-inch.

This is for the ammunition tanks only, and doesn't count any extra belt leading from the tank to the gun.

MAP data sheet for the 339E gives 250 rounds per gun for the fuselage .5s and 500 rounds per gun for the wing .5s (perhaps indicating the extra belt I alluded to?)
MAP data sheet for the 339B gives 160 rounds per gun for the fuselage .5s and 300 rounds per gun for the wing .303s

This is very interesting, thank you. I don't know if you saw, but I sent you a DM about these documents.

 

[FulmenTheFinn]

Here's an update on where my research into this topic is currently at:

Additionally one can calculate from the loadout weights mentioned in America's Hundred-Thousand, p. 440, that the F2A-2 and -3 were capable of carrying at least 900 and 1,300 rounds .50 cal respectively. One .50 cal round with its link weighed about 0.3 lb, while a .30 cal equivalent weighed about 0.065 lb.

EDIT: Updated 25 July 2025.

 

[taly01]

I tried to make sense of the F2A ammo loads also a while back. The trouble like you I found is some data seems too large. The F2A is a small plane with a fairly narrow wing.
But it looks like the wing gun ammo boxes were at the wing/fuselage junction extending into the fuselage body, so perhaps could be increased to hold 800 rounds, but it is still suspicious as the original F2A only had 200-220. Were the 220-450-800 rd gun wing ammo boxes completely different boxes?
The F2A-3 having more nose gun ammo is plausible as it moved the engine forward.

My thought is the space was always there, but from the 220rd of the prototype F2A-1, they went with F2A-2 the "new normal standard" 400rd of US fighters, but for the F2A-3 they were competing vs F4F and had to increase firepower so got 800 rd ammo boxes.

 

[Shortround6]

I think (without actually measuring the boxes/feedways) that people are somehow doubling the ammo in the wings at the very least. Turning 800 rounds in the "wing" to 800 rounds per gun for the wing guns.
AHT says 390lbs for the F2A-3 in overloaded bomber condition. That is about 1300 rounds of .50 cal ammo.
2600 rounds is 780lbs.
F4F-3s carried a max of 1720 rounds (430 rpg) 516lbs
and the F4F-4s carried 1440 rounds max (432lbs) for their 6 guns. They swapped ammo for gun weight.

800 rounds per wing gun means about 1 minute of firing time if the guns were the faster firing versions.

As a weight check, the Manual for the P-40D & E shows 300lbs for the design load of 1000 rounds for the 4 gun P-40D and max load of 738lbs for 2460 rounds.
The P-40E had a design load of 423lbs for 1410 rounds for the six guns and a max load of 561lbs for 1870 rounds.

I can understand being able to squeeze in another 20 rounds in a feed way leading from the ammo box to the gun, maybe. But 800 rounds of .50 cal ammo per gun is really going to cripple performance.

 

[ThomasP]

The USN F2A-2 PD (Performance Data) sheets from May 1943 list a maximum of 250 rpg for the nose guns and 200 rpg for the wing guns.

The USN F2A-3 PD sheets from December 1942[edit - changed 1943 to 1942] list a total of 1300 rounds.

If either the F2A-2 or F2A-3 as operated in US service could have carried more ammunition (possibly barring a few additional rounds in the feed chutes) the PD sheets would list it.

NOTE that the standard .50 cal ammunition box contained 100-110 rounds belted. Perhaps there was/is a misunderstanding as to how many rounds the "additional" ammunition box held?

??

 

[Shortround6]

The US did a lot strange stuff listing ammo capacities. Sometimes to make weight (many performance figures were done at less than max clean weight) and it wasn't just fuel that was not carried. Even the specs for the F4U were done with just 200rpg with the extra 200rpg (?) listed as overload.

Any F2A-2 or F2A-3s still flying in the Spring of 1943 (USMC had none in Dec 1942) were either at training bases or being used as squadron hacks.

Some of the USN PD sheets have occasionally doubtful information. Like listing 1600lb AP bombs for early versions of the SBD.
Pilot's manual for the SBD-3 has a gross weight of 9019lbs and with armor and protected tanks and a 1000lb bomb it can hold 100 US gallons (600lbs of fuel)
So either they retroactively significantly increased the gross weight or carriage of the 1600lb bomb meant leaving the rear crewman and some of the armor behind and a very short flight
I don't care if any SBD ever carried the 1600lb bomb in a combat area. What I care about is that every USN PD sheet from 1942 on lists the 1600lb bomb for every SBD ever built. And just about every SBD data sheet lists the insane 2250lb bomb load. (one 1600lb AP bomb and two 325lb depth charges).

 

[ThomasP]

Addition to the above:

I had forgotten that I had the armament section of the Detail Specification for the F2A-1. For the nose guns it lists the ammunition load as 600 rounds of .30 cal and 200 rounds of .50 cal, with 200 rounds per .50 cal for each of the 2 wing guns. So 600x .30 cal + 600x .50 cal total.

Additionally, mention is made of substituting a .30 cal for the .50 cal nose gun, giving 2x .30 cal in the nose and 2x .50 cal in the wings (1x .50 cal per wing). Presumably, it would have carried 600 rounds of .30 cal for each nose gun in this arrangement. So 1200x .30 cal + 400x .50 cal total.

Incidentally, the Brewster Model 239 Detail Specification lists the same armament combinations and ammunition load as for the F2A-1. The Model 239 Detail Specification can be found here "Brewster B-239 Buffalo Manuals" courtesy of Baball.

 

[ThomasP]

Whoops! My apologies, the F2A-3 PD sheets are from December 1942, not 1943. Edited my post#7 upthread.

 

[Shortround6]

Thank you for the Data Sheets.
They really do show the weight increase and the performance loss between the -2 and the -3.
Trying to carry another 390lbs of ammo would have been useless and the navy knew it as shown by the reduced weight (less ammo and fuel) in the first column of fighter and the greater load in the 2nd column.

 

[FulmenTheFinn]

The US did a lot strange stuff listing ammo capacities. Sometimes to make weight (many performance figures were done at less than max clean weight) and it wasn't just fuel that was not carried. Even the specs for the F4U were done with just 200rpg with the extra 200rpg (?) listed as overload.

Any F2A-2 or F2A-3s still flying in the Spring of 1943 (USMC had none in Dec 1942) were either at training bases or being used as squadron hacks.

Some of the USN PD sheets have occasionally doubtful information.

In my previous two posts I tried to allude to the fact that there is reason to doubt listed useful ammo loads as being the same thing as maximum ammo capacity. The detailed spec manual brought up by T ThomasP is the BAC report #350 I mentioned in 1) of the OP.

I'm particularly perplexed by MSgt Lauri Nissinen's combat report from 4 March 1942. 1,000 x .30 cal rounds and 1,500 x .50 cal rounds on an F2A-1-based Model 239? On an aircraft whose parts lists only talk about ammo boxes with a capacity of 600 rounds per .30 cal box and 220 rounds per .50 cal box? I've tried to find the report in Finnish to see if it's an improper translation and is in fact talking about the total ammo expenditure of the entire flight of Brewsters, but thus far I've only found it in English in Stenman's and Thomas' book. I might have to go digging for it in the Finnish archives. However in my experience these kinds of reports talk about personal ammo expenditure only.

Also, I'd missed this in America's Hundred-Thousand, which I'll add to my list of sources:

"The armament on the US Navy F2A-2 and F2A-3 was similar to that of the 239 except that both synchronized fuselage guns were 50 caliber M-2 models with a total round capacity of 500. The F2A-2 .50 caliber gun installation with 200 rounds in each wing was the same as the 239; however, the F2A-3 installation doubled the ammunition capacity to 400 rounds per gun."