AR Question. 9mm Upper + .5.56 Lower????

[Jack19]

If I wanted to put a 9mm upper on my 5.56 lower, I understand I'll need, obviously, 9mm mags and a mag-well adapter.

Is that all? Do any of the internals on the lower need to be changed? And,
if so, how does that effect my ability to also shoot 5.56?

 

[clown714]

only thing I needed was some sten mags and a

mag-well adapter.was good to go.had to get a mag loader for those stiff

mag springs.

clown

 

[Fly320s]

Not required, but a good idea, is to replace the buffer and spring with a heavier 9mm buffer and spring.

Also not required, but you may want to get a 9mm hammer or very slightly round-off the top of your .223 hammer so that it doesn't rub as heavily on the underside of the 9mm bolt.

This topic is discussed in depth, with lots of excellent photos, at www.ar15.com.