An ironsights feature was added by Miki45 (aka Happy Patch) as an unofficial addition to RealRTCW 2.1! Unfortunately, the feature is not considered complete and more work may be needed to complete it.
Miki45 will not be publishing this as a downloadable feature, but the source code for it was instead placed on the Pastebin link below. Any coders out there are welcome to finish and publish this feature, even if it’s not as an addon for RealRTCW.
Source code download link: https://pastebin.com/xsgM1yYP
Let’s hope that a coder decides to complete and release this ironsights feature for RTCW!
Source: Ronboy Productions