I ran across some Siacci ballistic coefficients for various types of Soviet ammunition. This is a different system from the ones commonly used in the West, so I ran some calculations and translated the numbers.
I don't know if these are "official" or not, but they appeared to be taken from some kind of Army cartridge data sheets.
As far as I could figure, the Soviet standard atmosphere described in ГОСТ 4401-81 is essentially the same as Standard ICAO. Ballistic coefficients from American companies seem to typically use Standard Metro, European companies seem to typically use Standard ICAO.
Here are some of the coefficients translated to G1, G7, G8 (under Standard Metro conditions, multiply coefficients by 1.018 for ICAO conditions)
148-gr steel-core ball, 57-N-323-S:----------0.381 G1----0.192 G7----820-835 m/s from SVD
148-gr 1908 Type "L" ball, 57-N-323:--------0.344 G1----0.188 G8----860-875 m/s from M91/30
182-gr 1930 Type "D" ball, 57-N-423:--------0.506 G1----0.254 G7----795-810 m/s from M91/30
There was also a Siacci coefficient for the 7N1 sniper cartridge, however, it was worse than that for standard ball ammo (C = 3.4). I figured there must have been a typo, and perhaps it was meant to be C = 3.04... if so:
152-gr 7N1 sniper:--------0.418 G1----0.210 G7----820-835 m/s from SVD
There were also coefficients for the following rounds, among others:
7.62x39 lead core, unnamed:----0.297 G1----0.149 G7---715-725 m/s from AKM
7.62x39 57-N-231-S:-----------0.309 G1----0.155 G7---715-725m/s from AKM
*Both standard weight 7.9-8g
7N6 5.45mm, 53 gr:-----------0.339 G1----0.170 G7---870-910 m/s from AK-74M
7N10 5.45mm, 56 gr:----------0.357 G1----0.179 G7---880-900 m/s from AK-74M
*document said 900-960 m/s, but Azerbaijan Ministry of Defense says 7N10 has a velocity of 870-890 m/s at 25m, another document says 870-895 m/s at 25m - must have been an error
In comparison to some ballistic coefficients tested at Aberdeen Proving Ground:
---------------APG-------G7 from Siacci values presented above----------------
M43:---------0.156------------------0.155----------------
7N6:---------0.168------------------0.170----------------
So at least some of these do appear to be fairly accurate, although there is no true confirmation of the other coefficients, at least yet.
Hope this helps anyone looking for data on these cartridges.
I don't know if these are "official" or not, but they appeared to be taken from some kind of Army cartridge data sheets.
As far as I could figure, the Soviet standard atmosphere described in ГОСТ 4401-81 is essentially the same as Standard ICAO. Ballistic coefficients from American companies seem to typically use Standard Metro, European companies seem to typically use Standard ICAO.
Here are some of the coefficients translated to G1, G7, G8 (under Standard Metro conditions, multiply coefficients by 1.018 for ICAO conditions)
148-gr steel-core ball, 57-N-323-S:----------0.381 G1----0.192 G7----820-835 m/s from SVD
148-gr 1908 Type "L" ball, 57-N-323:--------0.344 G1----0.188 G8----860-875 m/s from M91/30
182-gr 1930 Type "D" ball, 57-N-423:--------0.506 G1----0.254 G7----795-810 m/s from M91/30
There was also a Siacci coefficient for the 7N1 sniper cartridge, however, it was worse than that for standard ball ammo (C = 3.4). I figured there must have been a typo, and perhaps it was meant to be C = 3.04... if so:
152-gr 7N1 sniper:--------0.418 G1----0.210 G7----820-835 m/s from SVD
There were also coefficients for the following rounds, among others:
7.62x39 lead core, unnamed:----0.297 G1----0.149 G7---715-725 m/s from AKM
7.62x39 57-N-231-S:-----------0.309 G1----0.155 G7---715-725m/s from AKM
*Both standard weight 7.9-8g
7N6 5.45mm, 53 gr:-----------0.339 G1----0.170 G7---870-910 m/s from AK-74M
7N10 5.45mm, 56 gr:----------0.357 G1----0.179 G7---880-900 m/s from AK-74M
*document said 900-960 m/s, but Azerbaijan Ministry of Defense says 7N10 has a velocity of 870-890 m/s at 25m, another document says 870-895 m/s at 25m - must have been an error
In comparison to some ballistic coefficients tested at Aberdeen Proving Ground:
---------------APG-------G7 from Siacci values presented above----------------
M43:---------0.156------------------0.155----------------
7N6:---------0.168------------------0.170----------------
So at least some of these do appear to be fairly accurate, although there is no true confirmation of the other coefficients, at least yet.
Hope this helps anyone looking for data on these cartridges.
