I read through the tacked thread regarding headspacing and have walked away with more information. I read it and interpreted it as basically saying that the headspacing on a chamber should be between 1.4646" and 1.4706", while the Army considers a headspacing of 1.4730" to be safe, the USMC considers 1.470" (.223 SAAMI field) to be the max acceptable value.

Am I correct/safe/good to go by ordering just a .223 SAAMI Field gauge and using it for 5.56x45 NATO chambers? Would the headspacing be acceptable as long as the bolt (minus ejector and extractor) does NOT completely close with the SAAMI field gauge?

Here's the only one you need:

www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6646&title=5.56mm+(.223)+HEADSPACE+GAUGE

Quoted: Here's the only one you need: www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=6646&title=5.56mm+(.223)+HEADSPACE+GAUGE

Thanks for the link it will be a great help