Talk:Nudelman-Suranov NS-45

Tu-2Sh
According to Shirokorad, the NS-45 was also tested in early 1946 in a so-called Tu-2Sh, where two NS-45 were paired with two NS-37 in the nose. But this isn't matching the description of the Tu-2Sh tests we have in the Tu-2 article. Given that "Sh" simply stands for "Sturimovik" (ground attack), there may have been more than one variant; the Tu-2 wiki article also lists a couple of different gun loadouts for the Tu-2Sh. It seems more likely that with the NS-45 they were testing the future armament for their Tu-1 though, so I've not added as separate entry for that Tu-2Sh, lacking confirmation from other sources. Someone not using his real name (talk) 01:30, 27 July 2013 (UTC)
 * Actually there were three variants, per Gunston, p. 119. Someone not using his real name (talk) 08:24, 27 July 2013 (UTC)

Muzzle brake effectiveness
Both Shirokorad and Jakubowicz give the muzzle brake effectiveness of the NS-45 as "up to" 85%; this seems a highly exaggerated number, given how this particular muzzle break looks (rather small) and what we know about muzzle break effectiveness in general, so I've not added this claim to the wiki article. Someone not using his real name (talk) 02:04, 27 July 2013 (UTC)
 * I think the various authors, including Yefim Gordon are misreading some original source. Yefim Gordon gives as 5500 tons-force the recoil for the NS-37. That gun was not fitted with a muzzle brake; a fact that can be additionally verified by looking at the rather numerous Yak-9T photos as well. If we assume that the recoil reduction obtained by the NS-45 muzzle brake was 85% of the original recoil (i.e. the reduction was 15%), then we get a 5950 tons-force recoil for the NS-45 with the muzzle brake—a much more plausible number. The first test prototype for the NS-45 was actually a modified Yak-9T, so it makes sense the Soviet constructors were weary of recoil much in excess of that because the NS-37 caused some structural problems in the Yak-9 as well (mostly resolved by reinforcing the airframe). Someone not using his real name (talk) 06:54, 30 July 2013 (UTC)

Old data
I think I know where the data from the RAM page came from. Bill Gunston's 1987 encyclopedia (ISBN 086101314X) has: "Scaled up to 45mm in 1944, the resulting NS-45 was only fractionally heavier at 152kg (3351b), but fired 250 rounds per minute of 1.065kg (37.57oz) projectiles at 850m (2,789ft) per second with armour penetration of 58mm (2.28in)." There isn't a huge difference between this and the post-communist Russian sources, but I'm more inclined to cite the latter as Guston 1987 writing was still affected by the iron curtain. As far as I know no NS-45 made it to the West. (Chinn's 1952 [then classified] vol. 2 does not even mention it.) Someone not using his real name (talk) 11:45, 30 July 2013 (UTC)

AP shell
I've removed something I found in Williams, namely that "Armor penetration at 200 meters (at an unspecified incidence angle) increased from the 50 mm of the NS-37 projectile to 58 mm." Looking at the 50 mm penetration figure for the NS-37 was using an AP projectile. I'm guessing something similar was used for the 45 mm gun, because the MG-8 tippled AA/frag shell seems very unlikely to have had such performance. Unfortunately Williams does not mention what projectiles were used in the comparison, so it may be a bit WP:OR to assert something in the wiki article. The Il-2 tests for this gun, where it is more likely they would have tested AP, are unfortunately covered rather poorly (in terms of details) in every source I've looked at insofar. I have not seen the 58 mm penetration figure in a Russian source either; it probably came from Gunston's encyclopedia mentioned above. Someone not using his real name (talk) 12:14, 30 July 2013 (UTC)

Fuel tanks in 9K vs. 9T
Someone asked in the form of a HTML comment how much extra fuel was in terms of volume. The source cited in the article gives the extra fuel in Kg probably because it is in the context of discussing maneuverability. From another source (Истребители як-1,3,7,9 part 3), the 9T had 440-liter tanks, while the 9K had 650-liter tanks. This checks out ok at a density of around 700 kg/m3. Someone not using his real name (talk) 16:10, 9 August 2013 (UTC)