Flat Jig Question

[Lenzbenz]

I purchased the Jig from a Quarterbore member. Ran my 1st flat, and all holes including trunion line up great. I was a little concerned about the extra 1/16 inch gap on the top rail. ( Tapco flat w/prebent top rails) After trimming to fit the trunions I find that the bolt carrier is very sloppy on its top rail. Anyone clue me in to how that should fit? There will be no way to tighten it short of adding metal. Havent recd response from jig supplier although he swore it would work with the tapco.

Otherwise all looks good. Almost rivet time. Got a buddy with an aviation hangar and tons of bucking bars.

[Quarterbore]

I am behind the times but what is a "Tapco Flat with prebent top rails" do you have a link or photo?

The top rail is oversized to allow the receiver to be fitted to the parts. If this is pre-bent, then I would expect you could have a lot of slop in the top rail depending on the parts kit.

Also, have you added your center support and is everything riveted together? The other issue could be that the receiver is not to final shape without this so perhaps the top is just spread out more then it will be when you are done.

Again, I am curious about this flat... or not so flat, flat as the case may be?

[Lenzbenz]

Here is the link:
http://www.tapco.com/proddesc.aspx?Id=9a748c1a-64cb-4deb-8b9c-97228269cdfa

It is fully assembled except for bolt rails. My caliper shows 1.35 inch down full length. The jig I bought from your classifieds. When used I found the top rails about a 16th inch above the jig. But all holes for trunions matched perfectly.
I had to trim the rails to drop in flush on both trunions. Slight dremel work on magwell rear surface to accomodate mag and latch/release. It looks pretty good but I will need a better rivet set tool for next one. I borrowed a special aircraft rivet squeeze to set rivets inside of front trunion, after grinding a small rectangular adapter to drive below barrel mount surface. In any case i see about a 1/16 inch gap between carrier and rails. It allows about a total 1 inch side shake at front of piston.