Just imagine drop tanks on the Bf 109s in Battle of Britain.
The drop tank was first used during the Spanish Civil War to allow fighter aircraft to carry additional fuel for long-range escort flights without requiring a dramatically larger, heavier, less maneuverable fuselage. During World War II, the German Luftwaffe began using external fuel tanks with the introduction of a 300 liter (79 US gallon) light alloy model for the Ju 87R, a long range version of the Stuka dive bomber, in early 1940. The Bf 109E-7, introduced in August 1940, also used this type of drop tank, as did subsequent Messerschmitt Bf 109 and the Focke-Wulf Fw 190. The 300 liter capacity of drop tank became the standard size used in German service, and examples of drop tanks of that capacity were also made from non-strategic materials.
I suppose some kind of clusterbomb will be possible too.
I believe there was some German WWI cluster HE-frag bomb that was really put into use, and that it was post-WWI used also by Polish Air force and later on improved a bit, will have to dig the archives to find the name though...
it was "Myszka lotnicza nr.2", a small 1 kg frag bomb, dispensed from box-like cases. In 1930s it was modernised to Myszka lotnicza T wz.34.
http://pl.wikipedia....a_lotnicza_nr_2
An angled flightdeck on an early carrier would mean a much more speedy launch and recovery of big strikes.
I wonder if a wire guided bomb/missile dropped from high altitude would make level bombers a real threat to moving warships or be used against massive fortifications? Perhaps a wire guided AA missile for close-in defense of warships, or a wire guided torpedo?
A "Squid" type anti-submarine mortar is quite simple to build and use once you have Asdic and the idea.
The recoil less gun and the hollow charge principle ought to be possible much earlier, as ought man portable anti tank weapons like Panzerfaust or Bazooka.
Davis gun 1912 recoiless gun.
http://landships.activeboard.com/forum.spark?aBID=63528&p=3&topicID=9535077
Napalm?
Or what if the P-pill becomes widespread in the 1920s and the hippie movement blossom in the west in the 1930s - while Hitler goes on as OTL - bad pill, very bad pill...
Starting in 1927 with Kurt Beringer's Der Meskalinrausch (The Mescaline Intoxication), more intensive effort began to be focused on studies of psychoactive plants. Around the same time, Louis Lewin published his extensive survey of psychoactive plants, Phantastica (1928).
A versatile tank with sloped armour, a three man turret and a medium-high velocity gun in the 50-75mm range will be possible as soon as a reliable engine with 250+ shp is available. Ought not be a problem in the 1920s. A lot of 40-45 calibre 75mm naval guns with 600-800 mps MV would be available for main armament. Just need a revised recoil and recuperator system.
120mm and 81mm mortars as (Soviet and German) from WWII should be possible in 1920s and would give cheap, heavy and mobile firepower to infantry from batallion to Divisional level.
Stokes motar designed 1915 all other motars are derivatives of this.
http://www.worldwar1.com/dbc/smortar.htm
A bomber relying on speed rather than defensive armament (i.e. Mosquito) might add some realities to the claim: "The bomber will allways get through!".
The production Hart day bomber had a single 525 hp (390 kW) Rolls-Royce Kestrel IB 12-cylinder V-type engine; a speed of 184 mph (296 km/h) and a range of 470 mi (757 km).[10] It was faster than most contemporary fighters, an astonishing achievement considering it was a light bomber, and had high manoeuvrability, making the Hart one of the most effective biplane bombers ever produced for the Royal Air Force. In particular, it was faster than the Bristol Bulldog, which had recently entered service as the RAF's front line fighter. This disparity in performance led the RAF to gradually replace the Bulldog with the Hawker Fury.[11]
http://en.wikipedia.org/wiki/Hawker_Hart
Regards
Steffen Redbeard