9MM AR question

[patman]

With calibers being stamped on lowers,is it legal to shoot 9MM with a 5.56 lower?I'd like to build a 9MM AR pistol.I'd buy a pistol lower of course,but does it have to be stamped "9MM"?Or can I use a 5.56 lower with a mag block?

[chakup]

to my knowledge the caliber stamped on the receiver doesn't matter.

[patman]

OK.Does anybody know where I can get a 9MM pistol upper?Like maybe a 10 or 12" barrel?Been looking on the internet but can't find one.

[datsun280zmike]

rock river arms

[patman]

All I see from RRA is 16"ers.I guess I could buy one and have my gun smith chop it down.I'll have to order a pistol lower first though.

[datsun280zmike]

u dont need a pistol lower u can change the hammer to a 9mm hammer..check the info on rockriverarms.com

[Macros73_On_Road]

He needs a pistol lower if he wants a 10"-12" barrel and doesn't want to register it as a SBR.