After getting my HF press, I proceeded to shatter a 4" drill press vise, snap 2 pin punches into pieces, and bend a third one.  I think my Romy kit is trying to tell me something!  

Looks like I'll do a screw build, at least for the front of the receiver!

Drive screw build on the front end.

Try a 6 inch vise, a 3/8 socket ground to fit the trunion side, a really short 1/4 in. push pin, plus sucessively longer ones, and a piece of pipe on the vise handle.  Torque it down until the pin ALMOST buckles.  Then whack the movable end of the vise with a big hammer or hand sledge.  It'll probably move a touch.  Use longer pins as needed.  My worst case was a Tantal that needed a pin, made from a piece of a 1/4 in. drill shank, so short I only got in 2 vise cranks before putting in a slightly longer one.  The push pin got squashed, now looks like a little barrel.

Of my 3 Romys, one came out by hammer and punch easily, one in the vise with difficulty, one almost as bad as the horrible Tantal.  Only one gave an audible pop, and all the tough ones fought me all the way.

Pushing the barrel was similar, one with a hammer and socket, the others pretty tough using the Autozone pulley puller in a vise and a big long wrench to turn it.  Just be sure to shim the barrel breech with a piece of copper under a nickel or 2 so you get a straight push.

BTW, I heated them, soaked for a week in PB Blaster, froze, used receiver heating, air hammered - didn't help until I got the monster 6 inch industrial vise, made short push pins and cranked and whacked.

Also, push from right (looking forward, to left.  My pins were tapered a bit less than .001, assuming it didn't happen from all the hammering!