Basic trunion rivet question!

[Ted in Tallahassee]

I was talking to a buddy today and it became apparent that we had two very different ideas about how a Krinkov's trunion rivets are supposed to be installed while building up an SBR.

I say the mushroom ends go on the outside, and the cylindrical end passes through the sheetmetal receiver, through the trunion, and butts up against either the installed barrel or if no barrel's in yet, some kind of mandrel you place back there. Then you whack the mushroom end on the outside and the cylindrical part inside flares out, making things tight.

He says no, that the mushroom end goes on the INSIDE, and when you whack the cylindrical end poking out throught the sheetmetal with a special tool, it forms it into a mushroom shaped thing.

Who's right? With his method, one MUST install the trunion to the receiver BEFORE pressing the barrel in, or you've got to deal with spreading the receiver way out to fit the rivet-protruding trunion in place.

Who's right?

Ted in Tallahassee

[SClark]

i have ask this to before. the rounded head goes on the outside. then it is smashed from the inside against the trunion. then the barrel is put in. i had a maddi that i had teh barrel took out of and you could see teh rivets where smashed against the trunnion wall.

[Sturmgewehr44]

Uh, how the piss do we squish it from the inside?? Hitting the thing from the outside will just squash the nice rounded head, or mushroom the shank and won't let it go in. Is there a special tool to push from both sides?

Thanks for help!!

StG