Radeon

Greetings to everyone in the East from the West. I recently installed Custom and Love...I mean Love the look and feel as it takes me back to SoC when it came out. I am however having a ton of difficulty with the gunplay. This may not be the place to post for help but I have to use Google Translate to even read posts here. Can someone please assist me with these issues I have. Before I get replies about sucking and to get better and so on I play S.T.A.L.K.E.R for the immersion and fun factor. I am having issues with the AI difficulty in regards to them having perfect aim and their site. They instakill me and see me at extreme ranges through objects. I have played with the in game settings without results. Is there a mod in the pack I can disable or download to make it easier? Also the radiation is overwhelming for me. I love everything else though and want to figure this out. Thank you in advance.