I searched for about a year and found a used industrial bar-tacker on CL.
It's the bomb.
Loaded with Kevlar thread it makes a bar in about 3 seconds....keep your fingers back!
I'm told 4 bars are all that are required for a man-rated climbing harness....I usually lay down about a half a dozen.
Sweet machine -- let's us sew straps right on the swivels or with whatever loop we want.
I've never had one fail.
I think we paid $300 for it ... as a team investment it was money well spent!