America and Britain – two nations separated by a common cartridge* or how 7.62x51mm became the NATO standard * With apologies to Oscar Wilde, Bernard Shaw and others?

Dave Sutton, Phoenixville, PA

[email protected]

The Western Allies at the End of WWII

• Basic infantry weapons – US • M1 Garand firing .30-06 cartridge • Heavy • Semi-automatic – UK • Lee Enfield firing .303 British • Heavy • Bolt action

US – Beyond the Garand

• Greater firepower, light weight – Convinced that this had to include a cartridge with comparable ballistics to the .30-06 i.e. able to inflict a fatal wound at 2000 yards • Desire for a new and improved cartridge – Use of improved propellants from du Pont allowed a shorter cartridge case with similar ballistics to .30-06 • Shorter case • Shorter breach = lighter rifle • • Less materials for manufacture More cartridges per unit weight i.e. soldiers can carry more

UK – Beyond the Lee Enfield

• Need for a selective fire rifle • Recognition that the .303 cartridge was overkill at normal combat ranges – Willing to accept a less powerful cartridge using a bullet smaller than 0.303

– Small Arms Ideal Caliber panel established in 1945 • Aim for lightest rifle and cartridge acceptable for combat out to 600 yards

US Response

• March 1944 – Initial request for shortened .30 cal cartridge based on 300 Savage .30.06 - case length, 2.49” .300 Savage - case length, 1.87” • Mid 1944 to early 1945 – Testing of .300 Savage cartridges loaded with M2 bullets • January 1945 – Request for development of T65 cartridge

US T65 Series

No known examples Case type 30-06 .300 Savage 1944 T65 1945-1947 FAT1 1947-1948 FAT1E1 1948-1949 Commercial 30-06 head, decreased body taper, 1.871” case Increased neck length and extractor grove width, 1.951” case FAT1E2 ???

FAT1E3 1950-1954 Increased rim thickness, decreased extractor groove width, 1.951” case Increased body taper, decrease shoulder diameter and angle, 1.951” case Increased body taper, case length, base to shoulder, shoulder diameter, shoulder angle and neck length, 2.015” case

•

UK Response

Small Arms Ideal Caliber Panel – Formed 1945 • Extensive theoretical and experimental work – Final Report March 1947 • The Choice of a Standard Round for Small Arms – Caliber of about 0.27” if tungsten core unacceptable – Caliber down to 0.25” if tungsten core acceptable – Two cartridge designs approved • .280 - mid-1947 • .270 - October 1947 .303 British - case length, 2.21” .270 - case length, 1.81” .280 - case length, 1.70”

UK 7mm Series

270 280 Photo from Tony Edwards 280 Development of the .270 cartridge ceased in 1948 and future work focused on the .280 and .280/30 280/30 Extractor groove, rim and case head diameter modified to US .30 cal dimensions

The Political Scenario

• Change in British Government from Conservative to Labour in 1945 – US fears of Communist influence • Talks initiated on 1946/1947 between US, Britain and Canada regarding standardization of war materials including SAA – Apparent exclusion of the Soviet Union seen as the start of an alliance against Russia by certain factions in the Labour party who became openly critical of standardization • Creation of North Atlantic Treaty Organization (NATO) in 1949 to counter the military threat of the USSR

US-British Interactions

• 1947 First face to face meeting – US Ordnance flatly refused to consider the UK .280 cartridge on the grounds that certain bullet types could not be developed – The British learned about the .30 cal T65 cartridge for the first time • Convinced that the best light rifle could not be designed around the T65 cartridge • 1947-1949 Miniature arms race between US and UK – Britain suggests that tests of the two nations cartridges should be scheduled – set for early 1950 • 1949 Early test results of the US T25 rifle are encouraging – Britain, fearful that large-scale procurement of the T25 could kill off consideration of any British designs, requests that that the comparative trials now cover both rifle and cartridge

1950 Trials

• Aberdeen Proving Ground/Fort Benning – Head to head trials of US and British rifles that included evaluation of ammunition • Rifles US Springfield T27 • – – Ammunition UK/Belgium - .280

UK EM-2 US - .30 cal (FATE1/FAT1 cases) Belgium FN FAL • Trials took place over 6 months – Conducted with great fairness ensuring rifles and ammunition were compared under as near identical conditions as possible

1950 Trials - Ammunition

US .30 cal British .280

1950 Trials – Results

Accuracy Trajectory Penetration API ignition Tracer/observation function Ballistic coefficient

.30 T65

  

.280

   • Neither the rifles nor the ammunition was suitable for adoption without further modification • Recommendation that ammunition be perfected prior to designing the weapon • Need for agreement on a common cartridge before any further weapon comparison trials take place

US Army Issues with the .280 Cartridge

• • Trajectory – Unacceptable “safety zone” Safety zone 100 80 60 40 20 0 -20 0 280 Ball T104 30-06 M2 6' 100 200 300 Range (yards) 400 500 600 700 Performance in arctic conditions – Unacceptable muzzle velocity under temperate conditions would lead to serious problems at sub-zero temperatures • Difficulty in developing satisfactory special purpose rounds (tracer, AP, API etc)

Beyond the 1950 Trials

• Although the US trials effectively eliminated the .280 cartridge from further serious consideration, efforts were made to keep it alive – April 1951 - UK army adopts the EM-2 loaded with an improved .280/30 cartridge (7mm Mk1z) • US Ordnance – Protracted campaign to ensure demise of a 7mm cartridge with goal of ensuring that NATO adopt the T65 cartridge • Reality begins to sink in – UK and Belgium redesign EM-2 and FAL respectively for the US .30 cal cartridge – Feasible for the FAL, but not EM-2

The Path to NATO Standardization

• Mid 1951 – Joint meeting between US, UK, Canada and France to discuss SAA standardization • UK tries without success to sell the 7mm series • US continue to hold to their decision to adopt the T65 cartridge • France favor the T65 cartridges since the new 7.5mm semi-automatic rifle could more readily converted to the US cartridge • Canada look for standardization of one caliber whatever it is • This meeting effectively sounded the death knell for the .280/30 cartridge • Sept 1951 – NATO standing group agrees on set of military characteristics of required performance for any new SAA • Tests showed UK’s 7mm Mk1z fell well short

The Path to NATO Standardization II

• Late 1951 – The US Army officially rejects the .280 cartridge • “The Army is firmly opposed to the adoption of any less effective smaller caliber cartridge for use in either its present rifle or in new weapons” – New UK government reverse earlier decision to adopt EM-2 and the 7mm Mk1z cartridge • Reflected the reality of post-WWII Europe • UK SA industry not strong or big enough to go it alone • • Need for cooperation and standardization in light of cold war Need for US help in rebuilding Europe • The UK’s action effectively guaranteed the adoption of the .30 cal light rifle cartridge as the NATO standard

The Path to NATO Standardization III

• 1952 onwards – 1952 UK, Belgium and Canada form the Small Arms Development Committee (later referred to as the BBC) • Aim is to develop a 7mm cartridge acceptable to NATO 7mm Optimum 7mm High Velocity 7mm Compromise 7mm 2 nd Optimum

The Path to NATO Standardization IV

• 1952 onwards – BBC holds a series of trials comparing the various 7mm cartridges with .30 cal cartridges • Final trials held in mid-1953 compare various .30 cal loads against the 7mm 2 nd optimum cartridge – The US continues on with the T65 series regardless • T25 rifle dropped and replaced by the T44 (Adopted in 1957 as the M14) Springfield T44E4 – Sept 1953 BBC recommends selection of a .30 cal bullet in the FAT1E3 case

NATO Standardization

• Dec 1953 – NATO announces the T65E3 cartridge as the common NATO cartridge • Feb 1954 – Specifications agreed (finally ratified in 1957) • Aug 1954 – Formal adoption of the T65E3 cartridge as • Case, NATO Cal. 7.62mm

• Cartridge, Cal. 7.62mm, NATO, [type] – Belgium is the first country to use the new NATO design mark USA UK Belgium Canada France

7.62mm NATO cartridges (US)

Ball, M59, M80 Regular Tracer, M62 OHF AP, M61 Dummy, M63 HPT, M60 Blank, M82 Grenade, M64

7.62x51mm Retrospective

• Since its adoption in 1954 – – Manufactured and/or used by 60+ countries Replaced by 5.56x45mm as the main infantry rifle cartridge, but remains in use for • • GPMG Intermediate range sniper cartridge • Introduced to the civilian community by Winchester in 1952 as the 308 Winchester – Still in production over 50 years later • • • Excellent hunting cartridge Excellent accuracy Law enforcement role