Why does an extension cause my impact gun to have less torque? I have an impact gun that I can mount an extension onto. It appears the longer the extension, the less torque the impact gun delivers ? Does this make any sense , or am I just imagining things

 A: An impact wrench works by slamming the bolt head with a very sudden and sharp torque. The sharp hit is necessary to unstick the static friction between the underside of the bolt head and whatever it is screwed up against in the bolted part. Your extension acts as a torsional spring and by installing it, you dull out the sharp impact as the extension twists a little and delivers a slightly softer blow (over a longer time period) to the bolt head.  This makes the impact wrench less effective in unsticking the bolt.
A: You are not imagining things. Normally the impact wrench delivers a kick to the socket. Since the socket is light, it accelerates a lot.
With the extension, the impact wrench delivers a kick to the extension/socket combination. Both are accelerated. Since they are heavier, they are accelerated less.
You can see the same thing if you hit the socket with a hammer. It would fly across the shop. If you hit the extension/socket combination, it would not fly as far.
A: Extensions absorb the impulse of an impact gun and may render it useless. You may need to revert to a breaker bar.
