Headspace gauges 223-5.56

[Albroswift]

Looking online I see .223 Go-Nogo, .223 min max, 5.56 go- nogo, 5.56 min max, and one set that is labeled ".223-5.56"  min max but both have the 1.436 dim?. (Plus the associated field gauge Absolute no go?) Is there any difference between the 556 and the 223 SPECIFICALLY when it comes to these gauges?

 

[98Z5V]

The difference between them is in the leade, which is a chamber-reamer function.  The case length, shoulder distance and shoulder angle are the same.  .223 Wylde included.  Any gauges should work, as long as they're quality gauges. 

Field gauge is only for checking in-service weapons, not new ones.  If it swallows No-Go gauge, you test with a Field Gauge.  If it eats that one, time for a barrel.

Edited August 9, 2019 by 98Z5V

[Albroswift]

Thanks. The first 5.56 sig barrel  w/ stripped toolcraft BCG go gauge fit, no go was not even close. Then proceeded to shoot the ejector and spring across the shop, heard it hit something,  think it went out the door after that. Then proceeded to perform the same operation again except out the window, nothing but net. I've assembled bolts before without any special tools, but fingers  aren't as nimble as they use to be, time to order a n assembly tool I guess...

Anyway, tried to cycle some live ammo next, reloads that function fine in both Colts  (and fit the case gauge) were really tight/ sticky/ difficult to extract in the Sig barrel, but bulk factory ammo was fine. Range Sunday hopefully.

[mrraley]

This has always created discussions, arguments, and outright name calling.

The best thing that I will tell you is this... If your barrel is marked 5.56, then use gauges marked 5.56, if the barrel is marked .223, use .223 gauges. That way there is less chance of self doubt or confusion. But like @98Z5V said, the difference is in the reamers. 

There is a tech note from ArmaLite that is in Tech Notes #4 about head spacing.  

Edited August 9, 2019 by mrraley
add pictures, everybody loves pictures

[DNP]

Pffffff.  Facts - who needs those?  

[Cunuckgaucho]

[Cliff R]

"This has always created discussions, arguments, and outright name calling."

+2, 3, 4 and 5.

Spent 20 years as a military trained small arms instructor, qualified armorer, factory trained on several weapons, self trained thru years of OJT, even shot on a rifle and pistol team for a while, and still when I overhear (I try to avoid all that chit) discussions about the AR platforms in .223 and 5.56, at gun counters in some store or a gun show where "guru's" on this chit are abundant, there isn't a single time to date any of the folks spouting off all the specifics and arguing the details had a flucking clue as to what they were talking about.

"Anyway, tried to cycle some live ammo next, reloads that function fine in both Colts  (and fit the case gauge) were really tight/ sticky/ difficult to extract in the Sig barrel, but bulk factory ammo was fine. Range Sunday hopefully."

Factory ammo will tend to work better hand cycling them thru than "reloads".  Think about that statement for a minute and you woln't need for me to tell you why?.......Cliff

Edited August 12, 2019 by Cliff R