ar 15 could you take the 223 upper off and install a 7.62x39 upper ? also can you use the 223 mags ? not sure how all this works or if it does or not . thanks Bob

yes you can put any upper you want on it. youll need 7.62 mags. 223 wont work.

You can use your standard lower but will need 7.62x39 ar mags.

 

some good reading on the subject

http://www.ar15.com/content/page.html?id=558

thanks

The only real issues I have run into with conversion uppers tends to be with pistol caliber uppers, some need modified magwel blocks, some need modified hammers, some need different buffers etc.. Most of the time a rifle caliber upper receiver assembly and matching bolt/bolt carrier assembly are all you need to swap out.