billswagger
Airman 1st Class
- 256
- Mar 12, 2009
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
The 20 mm Hispano II in British use seems to have been perfectly reliable (details on Modifications and Attempts at Standardization ), so this was not a question of the calibre, but of the way the gun was built.
The table (1 - 2 % inaccuracy due to rounding in the original report):
600 yards and less: 96 %
400 yards and less: 86 %
300 yards and less: 74 %
200 yards and less: 52 %
It would be rare to kill something beyond 400 yards, and even rarer to do so by firing from a turn.
Hi Magister,
I notice that you edited your previous post after I answered. Any mismatch to my reply is your responsibility.
Though there are other factors, gravity drop is in fact one aspect.
However, it's possible to calculate approximate flight times from that table, and it seems that the Hispano 20 mm is considered to have a markedly higher muzzle velocity than the 12.7 mm Browning, which doesn't appear accurate.
What the tables illustrates nicely is that the difference between the trajectories of the 20 mm Hispano and the 12.7 mm Browning is small at typical combat ranges - 9 inches at 400 yards, where the pattern size alone is ten times that figure.
(What's the source of the table, by the way? Looks like an interesting docuement
Regards,
Henning (HoHun)