On March 31st, 1944, a demonstration of various British vehicles was held at the Lulworth proving grounds in Great Britain. The usual fare of British and American tanks were accompanied by something a little more exotic.
Comparative firing demonstrations means that we might get another penetration table done to one standard, like this one! Unfortunately, we are not so lucky, and the KV-1 only has the muzzle velocity recorded.
There are some interesting comparisons that can be made here nonetheless. Let's compare the numbers for tank guns present in both tables. The Tiger's gun penetrates 102 mm of armour at 1000 meters at a 30 degree angle, and 84 mm in the same conditions by Soviet standards (interestingly enough, the penetration at normal is almost the same). The KwK 40 from the PzIV penetrates 83 mm vs 60 mm by Soviet standards. Here, the penetration at normal is still significantly less than the British value. The German data disagrees with the British as well: according to them, the PzIV and Tiger's guns penetrate slightly less in these conditions, 82 mm and 99 mm respectively.
The British guns also perform significantly differently. By Soviet standards, the 6-pdr only penetrates 39 mm, while the British credit it with 53 mm of penetration. Same as the KwK 36, the gun does not performs close to British expectations when the plate is placed at normal. Interestingly enough, the gun had a higher muzzle velocity when tested in the USSR (837 m/s vs. 830 m/s). According to Soviet trials, the 17-pounder could penetrate 100 mm at 1000 meters and 30 degrees, versus the British 120 mm figure, which dispels the notion that Soviet-derived penetration values are lower than those in foreign tables because they are calculated.
The American 75 mm gun has a lower muzzle velocity (590 m/s vs 618 m/s on the British table), but once again falls far short of the Soviet standard: 63 mm in the UK, 39 mm in the USSR.