Airsoft Spring Pre tensioners

Had a player ask me for a solution to tickle the compression on a tired spring. Now, you should really replace a spring that's on it's way out, or is showing signs of sag, but if it's just on the borderline, then using an adjustable rear spring guide (if you have one) will buy you some time.....as long as you've not already wound it all the way in that is....or actually have one fitted.

I made these to suit most piston types - the ones that screw together through the piston head with the crap