SigAir ProForce MCX Virtus AEG airsoft gun: Part 5

by Tom Gaylord
Writing as B.B. Pelletier

Virtus AGE right
SigAir ProForce MCX Virtus AEG right side.

Part 1
Part 2
Part 3
Part 4

This report covers:

  • 110 mainspring
  • BUT
  • Prediction
  • Changing the mainspring
  • Assembly
  • Performance
  • 0.20-gram BBs
  • Rock and roll
  • 0.25-gram BBs
  • Battery
  • Summary

Today we’re going to have a little fun. I know some of you would like to work on spring-piston airguns but you just don’t want to jump into the deep end of the pool — as in buying expensive tools like a mainspring compressor and parts that may or may not work as you expect. Today we are going to change the mainspring in the SigAir ProForce MCX Virtus AEG airsoft gun, and we will do it with two Allen wrenches — nothing more! This is a job any of you can do. Then we’ll test the velocity of the gun and see what impact the new spring has made. read more