The Firing Line Forums - View Single Post - .223 v 5.56 Nato. The difference being...?

madcratebuilder · September 30, 2012, 06:53 AM

This should help.

http://www.gundigest.com/223-vs-5-56

A .223 chamber has a shorter leade, or free bore, than a 5.56 chamber. It's theoretically possible for a heavy (longer) bullet in a 5.56 round to be jammed in to the start of the rifling in a .223 chamber. This could theoretically cause a over pressure situation. The bullet needs to have a short free space for it's initial movement.

I use "theoretically" because I don't see any reports of this happening, and a lot of peeps use 5.56 in .223 chambers.

Commercial .223 brass can be thinner than 5.56 NATO brass. The NATO brass may have a smaller volume than .223 brass.

September 30, 2012, 06:53 AM	#3
madcratebuilder Senior Member Join Date: November 2, 2007 Location: Northern Orygun Posts: 4,923	This should help. http://www.gundigest.com/223-vs-5-56 A .223 chamber has a shorter leade, or free bore, than a 5.56 chamber. It's theoretically possible for a heavy (longer) bullet in a 5.56 round to be jammed in to the start of the rifling in a .223 chamber. This could theoretically cause a over pressure situation. The bullet needs to have a short free space for it's initial movement. I use "theoretically" because I don't see any reports of this happening, and a lot of peeps use 5.56 in .223 chambers. Commercial .223 brass can be thinner than 5.56 NATO brass. The NATO brass may have a smaller volume than .223 brass.