raider achievement problem

[Eriduan]

when i could see that i got the Raider achievement? because i killed that one sole guy (before the entering the station) like thousand times and nothing happened, i killed him by hellfire or sillenced rifle, headshot before he would even tunred on his personal light and still i didnt been notified by steam that i got the achievement. do i get it later or must i have something specific for that achievement, for example it works only with the Tikhar weapon?

[Jig McGalliger]

I think you have to use a silenced weapon for this, it worked with my helsing and tihar, not hellbreath. I only recently noticed that the enemies would know I was there if I killed the lookout without a silenced weapon. What gun are you stating is silenced?

[Eriduan]

I think it is silenced helsing, but wait i will tell you when i will be at nex trade station. because i dont know by the name. I still can switch the weapons if reload the game from beginning od prewious level. it is just railway part, lillte bit hard but at the previous level i can switch to tikhar.

[Eriduan]

okay .. by the wiki it is kalach 2012 silennced .. maybe that is the problem... :/

[Jig McGalliger]

All helsings are silenced.

[Eriduan]

okay .. i was trying untill finally got it .. it was hard but it was fortunatelly feasible