Was a little bored this afternoon and had a thought.  I took my lower off my 556r and put a AR mag Sig USA lower on it.  I have a Colt AR15 7.62x39 rifle, so I have some of the newer C-Products 30 round mags laying around.  Loaded one round in the mag, inserted it in the rifle, slowly worked the action and it fed into the chamber.  There is about an inch or so from the nose of the round to the chamber entrance, with no feed ramp or anything else to support the round entering the chamber.  I decided not to load the rifle using the full force of the action, so I don't know if you could fire it in this configuration.  Has anyone tried this?  I think the idea has come up here in the past.

You took a 556R lower off your rifle and put a 556 lower on it correct?

Then put an old AR platform modified AK magazine in it and was curious to see if it would function.

My first thought would be to make a few dummy 7.62 x 39 rounds and see if they cycle by hand.

I have a friend who had one of the Colt AK's and it never did function properly because of the magazines. He was very disappointed because he thought he had found the perfect rifle. I think if he were to visit the 556R today, he may come close to what he wanted.

It's Saturday...head to the range and answer the question for yourself and post the results.