The first upgrade of the original R-73 was the RMD-1 upgrade, which increased its aerodynamic range by 10km to 30km. Then came the RMD-2.
The K-74 has an aerodynamic range of 40 km and a 90 degree off bore lock angle and a 120 degree off bore tracking angle (seeker gimball limit, but target designation is at 90 deg). It's the most advanced of the R-73 family, and is made for export, with a new FPA seeker, more efficient TVC paddles (3% ultimate thrust loss, instead of 5% for the older ones) and a new nose section for the extended seeker gimbal limit. Don't remember when this K-74 was ready for export, but it was something like 1999 with flight testing completed back in 1994, while the R-73RMD2 entered RuAF service in 1994 (probably in limited numbers). Those are different modifications of the R-73, the RMD2 has a 60 degree designation angle and a 75 degree off bore tracking limit. Its aerodynamic range is the same as that of the K-74ME (export),: 40 km.
Slightly confusing, as western missiles can designate as far off bore as they can track, the R-73 relies on the radar and EOS for target designation coordinates for the 'normal' firing modes.
If we have the 'vanilla' R-73, then its ultimate range should be something like the 20km mentioned, if the RMD-1 version is moddled, then the range should be 30 km. The other two mods have bigger designation angles, so they're definately not moddled in lomac.
BTW, found some info in English on the control elements of the R-77 and R-73, just look at the corresponding diameters, 170mm for the R-73 and 200 for the R-77 :), from the makers themselves, so it has some credability :P
R-77, most left, Ukrainian designed self defense missile (R-73 replacement, made in 2006) second them the left, R-73 control section is the 4th from the left.
http://www.luch.kiev.ua/english/main.htm MAKE ED LOOK AT THEM for future projects, so all this whining and moaning can be put aside.