Time passes, friends become enemies, enemies become friends, but the need to know what your enemies are capable of doesn't go anywhere. Naturally, as the USSR continued its research into weapons, the United States continued trying to discover information on those weapons. This is what they came up with.
PAM 30-60-1 Vol. 3 Pt. 1 (composite image from several pages)
Lots of good old friends, as well as newcomers, so let's go through this list and see what we can find.
The first gun is the D-56T mounted on the PT-76 amphibious tank. It seems new and exciting, but it's actually just a boring old ZiS-3 in a tank form factor. So boring and old, in fact, that the penetration data comes straight from
this table right here, for APHE at least. The APCR data is not recorded in that table (probably because it has less penetration than AP at this range). HEAT is also new, and clearly a different round than was tested with the F-34. That one didn't perform nearly as well.
The next gun is the S-53, mounted on the T-34-85 and T-44. The rate of fire of only 3-4 RPM is rather low (average sustained RPM using all racks according to Soviet data is 6). The penetration for APHE is the same as the Soviet table again, but APCR is new, same as with the D-56T. Unlike the D-56, however, this round is actually more effective than AP at this range, which is probably why it doesn't get HEAT.
Next is the D-10T, from the T-54. Unlike with the predecessor, the rate of fire is straight out of the manual. Here, the penetration for AP is much greater than the old Soviet table (likely owing to post-war ammunition). The HEAT shell for this gun packs quite a punch, way above the dinky old D-56.
Now here's the good stuff, the smoothbore U-5TS from the T-62. The tank was built around the gun, and it shows. New APDS ammunition puts the D-10T to shame, and HEAT penetrated an impressive 450 mm of armour.
The D-25 is next, installed on every Soviet production heavy tank from the IS-2 to the T-10. Penetration here is a little higher than the Soviet table (160 vs. 147). Otherwise, there really isn't that many new things to be learned about it.
The successor of this gun, on the other hand, is much more interesting. This is the "122 mm T-10 tank gun", or better known to most as the M-62, mounted on the T-10M, but compatible with any D-25 mount. The AP shell of this gun penetrated 185 mm of armour at 1000 meters, which isn't that impressive. The bigger improvement is the HEAT shell, which penetrates a whopping 460 mm.
The next gun is a little more obscure, the 57 mm Ch-51M from the ASU-57 airborne SPG. The values here are lifted straight out of the manual (although APCR penetration at this range is listed as 101 mm in the manual instead of the 100 in the table). Looks like American intelligence was doing its job properly.
The next gun has a fancy title, but this is just the plain old ZiS-3 again. Comparing data with the D-56 will give you some differences in the mount, but otherwise, it's functionally identical.
The D-5S-85 is another gun you should be familiar with, from the Soviet SU-85 SPG. The same gun was mounted on the more modern ASU-85. As expected, its performance is exactly the same as the S-53.
The D-25S is another "double", with all data identical to its tank-based version, but in the end of the list, the ML-20 awaits! However, it doesn't have anything new to tell us. Penetration data is, once again, pulled straight from the Soviet table.
