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Old 7th October 2008, 03:49
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George Hopp George Hopp is offline
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George Hopp
Re: About WW2 fighter aircraft firing power

Quote:
2. Increase the rate at which projectiles are fired by increasing the number of guns or speeding up their rate of fire (N.B. The Luftwaffe preferred to fit 2x low-velocity 30mm MK 108 rather than 1x high-velocity 30mm MK 103 for the same weight, because the MK 108 combo put shells into the air at three times the rate). However, that requires a bigger ammo capacity and more weight again.
The Germans at Tarnewitz compared the two weapons in a report dated 7.9.43. They concluded several things:

1. For the weapon + mounting + accessories + ammunition for 20 sec. firing, the MK 103 weighed 259kg (taking a volume of .29m cubed space) and the MK 108, 214kg (volume, .10m cubed space).

2. They noted that that between 400m and 1000m,
with an attack from directly behind the MK 108 would score more hits.
with an attack at 15 degrees deflection, both cannon would score the same number of hits.
with an attack at 60 degrees deflection, the MK 103 would score more hits.
But, if two MK 108s were installed, weighing 428kg and taking up .20m cubed space, vs. the MK 103's 259kg and .29 m cubed space, the twin MK 108 armament would be more powerful than that of the single MK 103 under all circumstances.

3. While the MK 103 had a greater vo: 900m/s vs the MK 108's 525 m/s; it also had a far lower firing rate: 380/min vs. the MK 108's 680/min.

All the above data is from the report.
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