get the lp Vigilante it comes with the lp spring. go to http://www.g3pb.com/
then to the project/tech arrow, click there and at the top of the page it will say reg technical. click that and then chose the vigilante, this will show you the full disassembly and how to take care of it. the best tip there is to replace the reg seat of the vigilante with the type used in a mag, they work much better.