A retrospective: Bomber Command’s Browning .303-calibre Mark II machine gun


Browning .303s in Frazer-Nash FN13 rear turret of a Sunderland of No 210 Squadron at Oban – August 1940. Source: Public Domain via Wikipedia.

30th May 2016 (Updated 2 March 2017) | Nanton, Alberta. During the Second World War Royal Air Force (RAF) and Commonwealth Air Gunners’ lives were measured in days and weeks. Theirs was a thoroughly hazardous occupation. Not only did the men depend upon the pilots of the planes they were tasked with defending, but the weapons they operated were the last defensive measure, other than a corkscrew manoeuvre, an aircrew flying nocturnal missions could utilize to avoid or fight off attacking German Luftwaffe night fighters or to disable probing searchlights if at very low altitude. The Browning .303 Mark II machine gun was a staple of Bomber Command. Major advantages of the Browning .303 Mark IIs were that they were relatively light, accurate and available. Many continue to wonder why there was such reliance upon this gun when the Browning M2 .50-calibre was becoming a standard armament on American military aircraft. The paragraphs below present some answers, assumptions and analyses.

Browning .303s in Frazer-Nash FN-5 Nose Turret. Photo: Bomber Command Museum of Canada.

James Goulding and Philip Moyes state, in their book, RAF Bomber Command and its Aircraft 1941-1945, state (page 72): “The .303-in Browning gun was to remain the standard defensive armament of all our big operational bombers throughout World War II and this policy of the Air Ministry has always been the subject of much controversy.” Goulding also notes (page 73) that as a result the Browning have ever since been derogatorily assigned the moniker of ‘peashooters’ . . . by the critics. . . .”  Why was the decision taken by leadership to rely primarily upon the Browning .303-caliber machine gun in lieu of the larger 13.0-millimetre (.510-inch) and heavier (42 to 52 grams) projectile? There were a number of factors behind the decision taken by the powers that be to equip bombers with .303-inch guns; they included weight, reliability, rate and volume of fire, expected range and conditions of encounters and defensive tactics.

The Browning .303-calibre machine gun was adopted by the RAF as a replacement for the .303 Vickers and manufactured by Vickers Armstrong and BSA to fire the .303 round. The new model was designated Browning .303 Mk II in British Service. The weapon was essentially a 1930-Pattern, belt-fed, Colt–Browning machine gun with a few modifications. It was forthwith adopted for use as a Boulton Paul and Nash & Thomson turret guns in the Boulton Paul Defiant fighter and Handley-Page Halifax, Short Stirling, Avro Manchester, Avro Lancaster and other bombers. The .303 bullet’s diameter was 7.92 mm (0.312-inch) and it weighed 10 to 12 grams.

The weight issue weighed heavily upon the Air Ministry and RAF. Each Browning .303-calber weapon weighed (about 14 kilograms / 31 pounds) one-third of the M2 .50-calibre, which tipped the scales at 27 kilograms (64 pounds).

Any pilot will tell you that weight is a critical consideration when operating a fully-loaded aircraft. The RAF’s bombing machines were tasked with hauling tremendous loads of petrol and bombs over thousands of miles of enemy-controlled territory. Performance was of utmost importance, for the bomber pilots, labouring to maintain climb or cruise, considered stalls a constant possibility and concern. Those unfortunate enough to allow their aeroplanes to enter a stall and/or spin condition were in great danger of catastrophic aircraft structural failure or complete loss of control. This was especially true of the early marks of Handley-Page Halifaxes, which were underpowered and featured kidney-shaped vertical stabilizers that could not provide adequate stability for spin-recovery when the planes were loaded.

The book I Could Never Be So Lucky Again provides (page 204) a rationale. Inside U.S. Army Air Corps/U.S. Army Air Forces General (Ret.) James H. “Jimmy” Doolittle states that he reported the RAF preference for the .303 to his superior, General Hap Arnold, after his return from England in October 1941. Doolittle summarizes: “Their thinking is that the .50 will not pierce the new German armor and is useful, therefore, like the .303 for cutting tubing, controls, wires and generally disabling miscellaneous equipment. For this reason they feel that one shell is as good as another so they prefer the greater number of .303s available for a given weight.” Thus, during near encounters, such as those at night, the higher rate of fire of the .303 weapon could put more bullets onto a very fast-moving target in the very brief time an opposing aircraft was visible and most vulnerable — a point referenced by Goulding (RAF Bomber Command and its Aircraft 1941-1945, page 73).

Another consideration leading to the consistent use of the .303 was that the Browning M2 .50 was still experiencing some quality problems as late as March 1942. Jimmy Doolittle references (I Could Never Be So Lucky Again, page 228) this fact by writing the following about the .50-calibre weapons: “[W]e soon found they would not operate properly; some didn’t fire at all, and the best of them would fire only short bursts before jamming.” He continues,” The machine guns had been made . . . according to government specifications, but they wouldn’t work. The longest burst we could get was about five rounds.”

Comparative rates of fire are also interesting to contemplate. The Browning .303 Mk II possessed a rate of fire of 1150 rounds per minute. Thus, a 2-gun turret could spit out 2300 shells and a 4-gun turret 4600 bullets per minute at a target. Contrarily, the larger, more potent .50-inch calibre Browning M2 guns enjoyed a rate of fire of 1000 to 1300 rounds in the same period of time. Alternately, 2-gun .50 turrets were capable of emitting 2000 to 2600 projectiles with 60 seconds. Thus, the Browning .303s would spew many more bullets at an enemy aircraft than the longer ranging .50-calibre guns.

Furthermore, by 1944 even the Browning .50’s effectiveness was waning in view of Luftwaffe advancements in aircraft and armaments. In fact, after D-Day Jimmy Doolittle wrote (Doolittle, page 268) to his superior Hap Arnold asking for “larger-caliber, higher velocity (flatter trajectory) guns with better computing sights. . . .” Nevertheless, as stated on page 16 of FM159: The Lucky Lancaster,  Dave Birrell states: “Some significant changes were made beginning with the 186th Lancaster built by Victory . . . . the American-built, electrically powered Martin mid-upper gun turret with its twin .50 calibre machine guns replaced the British Fraser-Nash mid-upper.”

Perhaps, this change was in part due to observed Luftwaffe night fighter pilot tactics. Former RCAF Lancaster tail-gunner Bob Peterson told Airforce Magazine (Recollections from a Rear-Gunner, 2017 Vol 40/No. 3, page 32) that, “Their fighter tactics were to attack this position first, with the mid-upper next.” Often the enemy aircraft were not spotted until streams of coloured tracers darted forth out of the blackness, and the mid-upper gunner might have a second or two more time to get his guns on target and first a defensive burst.

Notably, Goulding (page 73) writes that the .303s “were, in fact, much more effective than many critics claimed, and our heavies claimed a considerable number of enemy fighters at night.” One must remember that a number of air gunners achieved an impressive number of kills while operating the Browning .303s. In fact, Bomber Command Museum of Canada highlights the remarkable stories of Peter Engbrecht & Gordon Gillanders of No. 424 Squadron, RCAF. In a raid on the night of 27/28 May 1944, Engbrecht, who was the mid-upper gunner for an RCAF-American pilot and RCAF Flight Lieutenant O. James G. Keys, in the standard 4-gun dorsal turret of his Halifax Mk III, while fending off at east 14 separate Luftwaffe interceptor attacks, shot down a Focke-Wulf Fw-190 and Messerschmitt Bf-110.

Fw 190A-3 in- June 1942. RAF photo – image MH4190 – Imperial War Museums.

The Fw-190 reportedly blew up in midair, whilst the Bf-110 exploded when it impacted the ground after absorbing Engbrecht’s accurate fire. In June, Engbrecht, with the able and timely assistance of rear-gunner Sergeant Gordon Gillanders, scored two more kills by shooting down a Bf-109 and Bf-110. Afterward, on 12/13 August 1944, these men again combined efforts to down a Messerschmitt Me 410 and Bf 109. These Luftwaffe victims were seen to flame and explode. Only 4 nights later Engbrecht claimed a probably destroyed. Goulding concludes (page 73), “[I]n the hands of good sharp-shooters like Engbrecht and Gillanders, the .303-in Brownings were quite capable of claiming a good toll of enemy fighters. . . .”

Bf 110 G-4. Source: Unknown via Wikipedia.

Another factor that must be addressed is the tactics utilised by the RAF. If a crew was fired upon from long range, gunners would instruct the pilot to use evasive action rather than waste ammunition on a distant, shadowy foe. An additional and practical consideration was that firing tracers in the dark could cause a gunner to lose sight of his target because the bright, burning rounds tended to momentarily destroy one’s night-adapted vision. Another negative consequence of firing at prowling fighters was that the strings of coloured tracers acted like tiny flares and could result in the attraction of nearby enemies who were previously unaware of the presence of the RAF plane. Thus, a standing directive was to not fire until fired upon; gunners were instructed to hold their fire until necessity and urgency gave them no choice.

Notably, if .303-inch guns were triggered Luftwaffe fighters could be kept at bay, a finding that Bomber Command Museum of Canada‘s online article Air Gunner Stories echoes when it states the following: “Good gunners could, with a few bursts, force most night fighters to work at long range, spoiling their aim . . . .” This analysis was essentially confirmed by Luftwaffe Messerschmitt Bf 110 pilot Peter Spoden in the 2005 documentary Halifax At War: The Story of a Bomber. Herr Spoden indicates that that once a bomber stream had been located he and his colleagues would “be very fast” to enter and “who was seen first was shot down first.” This sentiment was echoed during the war by RAF tail gunner Richard Rivaz on page 44 of his classic work Tail Gunner: “I did not intend him [an enemy night fighter pilot] to have a shot at all if I could see him first!”

Lastly, as the documentary Bomber Command Air War over Germany points out, the overall goal of arming the bombers was to “provide a reasonable measure of defence.” The .303 served this limited purpose. Faster and more manageable Luftwaffe night fighters, usually armed with one or more 20-milimetre cannon, held tactical advantages over their prey. This fact of aerial combat was not negated by the incorporation into British bombers of .50-inch guns, for even the vaunted .50’s range was inferior to that of the 20-millimetre.

Despite their shortcomings, Aaron Carter indicates in the 30th December 2015 issue of American Rifleman magazine, that marksmen and hunters continue to derive pleasure and achieve results from firing .303 British bullets. Commenting on a photo forwarded to him that recorded the kill of a wild boar knocked down at distance by a pilot and hunter in Arcadia, Florida with a venerable Lee-Enfield Mk. III SMLE. The replying Lee-Enfield Rifle Association (LERA) official in England wrote the following: “For an old girl, she still packs a respectable wallop.”

Diver recovers .303 machine gun. Photo: Halifax 57 Rescue (Canada).

And .303s continue to enter the news. Only a few days ago a Halifax bomber that shot down during the Second World War and is resting on the seabed off the coast of Sweden. It is currently being surveyed prior to recovery by Bomber Command Museum of Canada, Halifax 57 Rescue (Canada) and Swedish dive teams. The wreck quickly rewarded the searchers’ initiatives with the find of one of the bomber’s .303 Brownings.


The author (John T. Stemple) thanks Bomber Command Museum of Canada and Halifax 57 Rescue (Canada) for supplying information and images for this article.

Suggested Viewings

Sources and Suggested Readings

.303 British


.50 BMG


A Halifax Rear-Gunner


Air Gunner Stories


Air Gunner Tactics


Air Gunners – Weapons


An Air Gunner Remembers: RAF Training and Service with 625 Squadron


An American in the RCAF


Birrell, Dave. FM159: The Lucky Lancaster. Nanton: The Nanton Lancaster Society, 2015.

Bomber Boys: The Fighting Lancaster Episode #3. Frantic Bomber Productions Inc., 2004.

Bomber Command: Air War over Germany. Scortched Earth. Eagle Rock Entertainment. 1999. (DVD).

Browning .303 Mark II Machine Gun


M1919 Browning Machine Gun/Browning .303 Mark II


Browning M2


Browning M2 Machine Gun


Doolittle, James H. and Carroll V. Glines. I could Never Be So Lucky Again. New York: Bantam Books. 1991.

Engbrecht & Gillanders – RCAF Air Gunners


Goulding, James and Philip Moyes. RAF Bomber Command and its Aircraft 1941-1945. London: Ian Allan Ltd., 1978.

Gun Turrets


Halifax at War: The Story of a Bomber. (DVD) Nightfighters Products Inc., 2005. ISBN 978-1-55259-974-7.

Halifax 360VR Tours


Handley Page Halifax


Handley Page Halifax


Handley Page Halifax III


Handley-Page Halifax


Latest Loads: .303 British


M1919 Browning machine gun


Messerschmitt Bf 109


Messerschmitt Bf 110


Messerschmitt Me 410


Milberry, Larry. Sixty Years – The RCAF and CF Air Command 1924-1984. Toronto: CANAV Books, 1985.

Recollections from a Rear-Gunner.  Airforce Magazine. 2017, Vol 40/No. 3.

Rivaz, R.C. Tail Gunner. Gloucestershire: The History Press, 2011.

The Air Gunner Collection


The Americans In The RCAF


The Handley Page Halifax Armament


The Lee Enfield Rifle Association (LERA)


Those Other Heroes: RAF notable bomber gunners in WW2