Cut down rear trunnion rivets would work for the shorter ones. I wonder if you could source mild steel round stock of the right diameter to make longer rear trunnion rivets.
I have cut down long rivets and sometimes it worked and some times they were a little loose, like their diameter was a little off. A little bit more love, and I donstress a LITTLE BIT, resolved the issue whenever it does occur.
As far as mild steel dowels, doming one side sucks bad enough, let’s not double the amount of peening and hammering
One of my goals is to get a milling machine capable of making milled receivers and make them commercially. Milled receivers are cool because I don’t have to drill, flex them straight on a vice and all the other little things a stamped receiver needs
AR guys couldn’t do this. They’d lose patience. And if they did try, they’d probably respect us AK guys a lot more from a building perspective