AR 9mm conversion

Laredo Lefty

When putting a 9MM upper on a .223 AR lower, does the .223 hammer need to be changed to a 9mm specific hammer or will the .223 version work?

Thanks

gsmith

I have had the 223 hammer ( with the hook ) work. Try it, and if it does not work, just remove the hook.
Good Luck,
Gsmith

Nwcid

Most set ups say that it is required. I believe the new RRA can use either. You CAN use the 9mm for both.

dcs shooters

I had a Colt upper on a Bushmaster lower and it had a stock hammer in it, and worked fine.