7.62 Hard Life is a fanmade enhanced version of 7.62 High Calibre (sold as 7.62 mm on this site).
Gameplay video: https://www.youtube.com/watch?v=k6wRUQggDhY
Screenshots can be found on the Steam page linked below, or check the 7.62 High Calibre page linked above as they're similar.
Since it's nicely described on Steam, I've copied their description:
7,62 Hard Life is a fan made enhanced version of the original tactical sim 7,62 High Calibre. Its development started almost immediately after the original game release in 2007. Over 50 people worked on the project in total. We hope you'll enjoy this version, that is available to all owners of the original game on Steam at no extra cost. Today Hard Life addon contains: 25 additional locations, including ones taken from addon 7,62 Reload (which was released in Russia only) and new ones made from scratch; around 30 new NPCs; more than 100 new story quests, including the possibility to complete the game without joining any side of the conflict, and numerous side quests; more than 1000 new items, including 130 new weapons; ability to fine tune the gameplay and functionality to your tastes (adjust an amount of enemies, Iron Man mode, hunger and thirst modeling, enhanced transport system, limiting an amount of cash NPC traders have and so on); many fixes for the bugs of the original game; widescreen adaptation; other improvements. Addon is available in Russian and English languages.
On Steam it's available for free for owners of 7.62 High Calibre.
It has mostly positive reviews on Steam.
Platform: Windows XP, 7, 8, 10 (according to the Steam page)