Final draft: https://www.royalroad.com/fiction/62486/guns-and-magic-in-the-light-of-the-scarlet-sunset

Blake is a retired soldier with PTSD syndrome and a dark past, living in the early twenty-fourth century. The only medicine that helps to cope with the symptoms is a VR game. «Guns and Magic» is an exceptional game created with the Government's and the Ministry of Defense's support, where players use old, twentieth-century weapons to achieve their own goals, but magic is just at an arm's length too. "Thalack" is a unique virtual world where levels without skills mean nothing, with complex mechanics of moral choices and huge penalties for death. In the struggle to be the best, the developers offer to fulfill the top player's wish. Blake accepts the developers' challenge and becomes Ronnie. Ronnie is character who combines the rare craft of a gunsmith with the deadly shot of a sniper. With his trusty Barrett M107A1, he's ready to take on the world.PS. This is the first draft. Soon I will publish rewrite, in which I have changed a lot, thanks to the advices of readers and reviewers.