Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
2/7/2009 11:17:53 AM EDT
i have a rra .223  and was going to buy a 9mm ar but i was wondering if i bought a 9mm  upper can i just put on the lower without modifacation?  I only ask cause ive been told two diffrent things.  thanks
2/7/2009 12:14:21 PM EDT
[#1]
If you use a DPMS Rounded top hammer, and a drop in 9mm block then yes! Thats how I have mine setup.
2/7/2009 12:20:29 PM EDT
[#2]
You need a heavier buffer too if you're running a collapsible stock.

The rounded DPMS/no-notch hammer will work with 223.  Once you swap that out you don't have to do it again.
.223 ammo will usually run OK with a 9mm buffer in place (assuming you don;t have one of the special long buffers).  So you don;t have to swap that out either.

Once set up, you just have to install or remove the magazine block and upper.

I'd use a bottom Hahn block or RRA block in this application.
AR Sponsor