On Sun, 27 Dec 2009 22:30:59 -0800 (PST), "SonomaProducts.com"
wrote:

FYI, most Senco roofing and siding type guns are made to be bounce
fired like roofers do, just hold the trigger and bounce as many times
as you want. So it fires an "indeterminate" number of nails or staples
per trigger pull. This can cause double fires quite easily if you are
using it like a shop tool. You can get a "determinate" trigger upgrade
from Senco. Call customer service and they send it for free. It is
just a little spring thing and not to hard to install. All internal so
it feels the same after you install it.

I thought of that. This one doesn't have a bounce trigger. I don't
know if the previous owner put a new trigger in it or what, but that's
not the problem. I could probably use a new set of O-rings, which I
have but I only needed the nailer to reside the garage on my last
house. ...and I've got a half a box of stainless nails sitting in a
bin with it and the O-ring kit, where they'll probably be for the next
decade. ;-)