Automatic Gunfire: Halfway Between VY and Brattleboro in Vernon ?

On 5/8/2016 I heard automatic gunfire coming from Vernon. It is the sneaky nature of it. I heard it from about a mile or two north of VY. I was riding my bike at about 6 pm along the Hinsdale railroad trail. I am thinking it was in the gavel mine area.

The first auto burst had about maybe a ten shots. The auto burst had about 2-4 shots. 

 Between them there was about a five single shot bursts. Maybe five shots, then maybe a 20 minutes wait, then repeat another four times. Then one automatic burst of maybe 4 shots ending the show. It sounds like they were setting the gun's sights. If it would be drunken yahoos, I thinking they would waste a lot more ammo entertaining themselves.   

I am thinking the terrorist are getting ready to strike. I wouldn't be surprised seeing a local mass causality event popping up in the news.  

1) Attack VY (unlikely now) 

2) Attacking one of our schools or hospitals?

3) A local fair or something: any high concentration of the population? 

4) Strolling of the Heifer comes June 5?