QUOTE (desert dog @ Dec 4 2008, 07:33 AM)

Tony, I had also never seen a trunion like this, thats why I posted, it left me scratching my head when it was time to put in the bullet guide. The pre-drilled hole is also quite large, too big to tap (the screw head would be too big to fit the contour of the bullet guide).
To rivet it in, Take off handguards, slip a piece of 3/8" thick x 1" wide steel bar between trunion and reciever (from the front). Set gun on flat metal surface and punch that rivet in from the top. It only took a minute. I got the idea from someone's post on the AKfiles.
Punch it in with what? A press? A hammer and punch? An air hammer?
Did you set the rivet into the hole from the top (meaning that the rivet head was pointing up?)
How long was the rivet?
Here's what I came up with (considerably more difficult, but it worked well and formed the correct heads on the bottom and top, and it didn't transfer any force through the receiver):





Basically I drilled a hole through the bottom of the receiver. This allowed me to stick a hardened pin thru the bottom of the receiver to act as a support for the bucking bar. This transferred the mechanical energy of the 20-ton press directly through the rivet and into the base of the press fixture. No pressure was applied to the bottom of the receiver. I then had to weld the hole closed.
I considered all sorts of strategies like the one you chose, which basically attempts to "fill the void" in between the bottom of the trunnion and the bottom of the receiver with some sort of bucking bar... The problem of course is that the "void" is not a simple rectangle - it's a parallelagram due to the fact that the receiver bottom is angled relative to the bottom of the trunnion. I'm still curious to see some photos of how your rivet turned out (both from the top and from the inside of the bottom).
There are other complications, here, such as the fact that the bullet guide is a concave surface, so I had to make a press ram with a matching convex surface to correctly 'squash' the rivet into the curved bullet guide.
Sorry but when folks post a simple one or two line description of setting a bullet guide rivet in a Saiga, it really gets me curious - and the method you described appears to have worked for you, but it seems like there's a bit of a risk for damaging the receiver and/ot getting bad squash on that rivet.
-Thirtycal