gottschs said:
I always wondered why the Russians skipped over the 14.5mm and went to the 12.7mm or 23mm for aircraft weapons.
The 14.5mm has a very flat shot (as opposed to the way the 23mm arc'd) and it hit much harder than the 12.7mm.
I realize the use of machine guns of the 7.5-7.9mm were very useful for volume shooting versus manpower.
Just wondering.
It would be interesting to see the Soviet Russian arguments for skipping over the 14.5mm gun. It's worth looking at the German experience.
When the Me 109F1 was introduced it also introduced the MG 151 canon with a calibre of 15mm. This gun has a very high muzzle velocity and was explosive filled. It replaced the 20mm MG FF/M on the Me 109E7. Me 109E1-E3 were armed with the MG FF and from the Me 109E4 onwards the MG FF/M which was the same gun with minor modifications to fire the lighter and faster Minenengeschuss which were thin walled and filled with more explosives.
The MG 151 15mm was liked by many pilots who were good shots, its long range, accuracy and flat trajectory allowed them to get high hit rates. The MG 151 15mm however not so good for average pilots who could not get as high a percentage of hits and I suspect it did not perform well against bombers and soon most MG151 were the MG 151/20 which had a much heavier round with more explosive filler fired at a still respectable velocity.
In the same way that the Germans necked out their 15 x 104 mm to 20 x 104 the Russians necked out the 14.5 x 115 to create 23 x 115. So, in a way, they made the same decision as the Germans.
The MG 151/15 was equal to the Soviet 14.5mm in ballistics. The MG 151/20 had inferior ballistics but they were still good to 500m and had a much more destructive shell.
The VVS however made little use of the 23mm except on some ground attack aircraft. They used 20mm ShVak and 12.7mm (which could replace 7.62 in most cases)
So the Russians would have face the same problem: the 14.5mm gun was accurate and had good ballistics but not enough destructive power for the weight carried in an aircraft.
The 23mm gun was significantly more powerful than the MG 151/20 in terms of muzzle velocity and shell weight and in fact the British variants of the Hispano were also more powerful than the MG 151/20 in terms of velocity.
The other problem with the 14.5mm gun is that its just too big to be used on a flexible mount and to fit into locations such as an synchronised engine mount.
For instance the German 13.2mm MG 131 with its 13.2 x 64mm round was less powerful than the US 50 or Russian 12.7 or 14.5 but its strength was an much higher firing rate than these guns and the fact it could replace 7.92 mm rifle calibre guns in compact nose mounts yet had 2-3 more times the destructive power and penetration than rifle calibre. In fact the bullets could be explosive filled.
The Soviet 14.5mm seems to have developed as an AT gun round to replace or supplement the 12.7mm. When converted into a machine gun it was too heavy for troops. It was found very useful for Anti Aircraft use. This weapon was an army weapon and just not ready until mid war, it entered service as an AAA weapon in 1944.
The German 2.0cm FLAK C30 and C38 had different rounds and cartridges to the MG 151/20 both much heavier and with much higher velocity. I don't believe they were ever used in an aircraft.
If the Germans needed FLAK they used their MG 34 or MG 42 with the tripod (which was an effective AAA mount) or they upsized to the 2.0cm C38 in a hand cranked, geared heavy mount that guaranteed accuracy for the massive recolil.
Another issue was likely synchronisation. German MG 151 and MG 131 could be electrically synchronised via electrical primers. The Russian 23mm gun could be synchronised (I suspect hydraulically). A synchronisation mechanism may just not have been worth developing.
The MG 151/15 seemed to still show up in some German aircraft projects eg Dornier Do 335 because its ballistics matched the larger Mk 103 30mm canon.
MG 151/20 were used for FLAK but only because of a shortage of C38 guns.
The 14.5mm barrel would also have been long compared to the 23mm, difficult to install.
