Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
2/8/2014 5:45:11 PM EDT
I am starting a build with a 5.56 NATO chambered barrel. When I get ready to check the headspace will my .223 headspace go and no go work or do I need to buy the 5.56 go and no go. Is there any difference?
2/8/2014 6:00:47 PM EDT
[#1]
they are the same.(headspace) The differences between 5.56 and .223 are in the throat/leade area.
2/8/2014 8:12:47 PM EDT
[#2]
A 223 REM match gage set works for both.
The difference is in the headspace spec not the type of gage.
223 REM Go 1.4636”.
556 NATO Go 1.4646”.
223 REM No-go 1.4666”.
556 NATO No-go 1.4706”.
AFAIK at this time both SAAMI and the military accept the Colt spec max chamber gage 1.4736”.
Note that failing a 1.4706” gage is a reject point for new 556 barrels.
AR Sponsor