Look these pic and look the nice work of the modeler of infiltration.
http://www.geocities.com/euh_what/infiltration/psg1.jpg
http://www.geocities.com/euh_what/infiltration/mp5.jpg
http://www.geocities.com/euh_what/infiltration/magnum.jpg
http://www.geocities.com/euh_what/infiltration/psg1.jpg
http://www.geocities.com/euh_what/infiltration/mp5.jpg
http://www.geocities.com/euh_what/infiltration/magnum.jpg