ive noticed that the mechanical horns in my collection 9838-9833-9806 etc sound much louder when they sound in my home rather than in a school that uses those horns in cont. where i conduct drills. is this acoustics in the bldg or is there a way such as the pitch
metal lever or something else to lower volume. or could it be that the voltage and current drop cause them to sound quieter?
It could be many things: The acoustics and shape of the hallways and buildings like you said, your homes walls aren’t made like the ones in your school. The ones in your home are made to dampen noise. The ones in your school are built to be strong and protect. That is why the safest place is a school. 
The screw on the bottom I’m not quite sure so I’m just gonna let Andrew or Destin or someone else answer that part of it.
Some i agree with
If your under-powering, it would sound raspy.
The acoustics of a school usually don’t have “Fabric Floors”(Carpet, Other types) , most houses do.
Yes
Yes we should do that
I meant stuff like storms. There’s not much that can stop a fully automatic riffle…
Edit:Anyway back on topic.