The AA12 by Narcis_speed6
My first gun made using 3DS, has few bugs and other texture problems but is still beta and will be solved in future
The .rar contains 2 versions of guns
Install:
Replace (recomended) chromegun.dff and chromegun.txd from gta3.img with Alci's img editor or Spark
that's all
have fun!
MORE DETAILS AT MY TOPIC
http://www.gtaforums.com/index.php?showtopic=431900