On Sat, 21 Jan 2012 18:47:00 -0500, "Twayne"
Not in my book. When doing framing or roofing, bump fire
can be a good thing. When doing fine stuff, it's not
necessary.

Who makes such a gun; any idea?

??? Everybody makes such a nail gun. It's a common feature of many
nail guns and is a practice used by almost every contractor especially
in the framing industry.