We felt it pretty good.... but it didn't affect us here in Missoula. A nice good rocking motion, but thats about it. Lights and doors were swinging, but nothing fell over or fell from shelves.
There are a few firearms businesses in Dillon though, and I'm sure they got much more shaking than us! KT Ordnance who does the 80% AR receivers is one of them, as is Lawton Machine who does barrels and actions.
I just got off the phone with Barney and everything is fine with his shop. He said that they just had another quake just a couple of minutes ago, but it wasn't as bad this time. He did say that he was running the CNC mill when the first one hit, and it caused the bit to take out a chunk about 1/8-3/16 of an inch out of the piece he was tooling.
Hopefully this last one wasn't as strong up your way Mel.
Looks like it was a 4.2 from that link posted above. About 12 miles from Dillon.