K&M Lightening


Trigger job / fix for the MSAR STG 556 : NOT for any of the Steyr Aug versions.


The Lightning was developed from a stock trigger pull that averaged 9lb. 4oz over 10 pulls with a digital Lyman gauge. This trigger fix is the lightest on the market to date and does not modify any item on the firearm. I have measured others that will not even measure on the gage which maxed out at 12Lb.


The lightning has 3 positions to choose from.  The top slot is the lightest at 4lb. 5oz.  The middle position is 5lb. 1oz and the lower slot is 6lb. 3oz.


One thing to note about the top position; It is so light that if you pull the trigger and keep it pulled back it will not reset during firing, but if you pull the trigger and release the trigger, it will reset with the slam of the bolt.  It only does it on this position, the other two positions work flawlessly.  This happens because there is so little spring tension on the trigger pack that it needs a little jolt to retract it by itself. This in no way will let it go full auto!


This item will NOT work in the Steyr Aug versions. Because if their rear butt pad pin design there is not enough pressure on the pin because of the reduced spring tension to keep it from falling out.


I have listed below other rifles that I have and what their trigger pulls are for reference.

Stock mini 14
5lb 1.5oz avg

Stock bushmaster ar15
6lb 12.5oz avg


Stock DPMS ar15
7lb 1oz avg

Bushmaster M17s
9lb 10.5oz avg


K&M Lightning


Install Instructions

You tube video

1 Pack-$40

2 Pack-$75


3 Pack-$105


NOTICE: Never clean your trigger pack with an aerosol type cleaner like Winchester Break free. These type of spray cleaners/degreasers will attack some plastics and ruin your parts. So please only clean with solvents that are safe for all plastics. It is best to just run your hammer pack dry with no lube as this is how it came from the factory.