Hi ZVP,
I LOVE that little $90 gun (in late 1980's dollars - 1988 or 1989 I believe)....still one of the BEST and most consistantly accurate, and undestructable guns that I have ever had or shot, believe it or not!!!
This may sound like BS (that is what I have been told over the years when I say this)....but my buddy who bought his .177 3100 2 days after I did, used to sit with me in bunches of overgrown Casterbean bushes (that was our shooting blind) at the side of a little pond...horrible as it sounds, we could knock Hummingbirds out of the air as they hovered about 20 feet above our heads...that was shooting CHEAP wad cutters and some funky brand of pointed pellets from K-Mart. Never put a scope on mine....had open sites with the front being like the J. G. Anschutz - Metal Aperture Inserts like the one pictured below.
BTW....I don't shoot hummingbirds anymore...just feral Pigeons, Desert Jackrabbits, & stray Coyotes that are a bit of a plague here in the desert.
I am going to California this Monday for a week or so to give a lecture to some Attorneys regarding computer security, but I would LOVE to talk to you about this gun via email, posts on this site, or on the phone...sounds like GREAT fun!!
I modded my trigger a TINY bit, so I am sure that I can help.....I hope!
-Curtis