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4/10/2002 2:02:37 PM EDT
This topic may have already been discussed but I got into an argument with some on the diffences in a 223 chamber and a 5.56 chamber. Basically an ammo dispute.I've also heard that a 223 chamber is tighter and not to put 5.56 ammo through it, due to pressure differences. He says the opposite. Who's right?[:\]
4/10/2002 5:25:57 PM EDT
[#1]
You are right.

The military M16-spec chamber (commonly referred to as the 5.56 NATO chamber) is larger and has a longer throat to reduce chamber pressures with hot-loaded military ammo.  Commercial .223-spec ammo will work just fine in 5.56 chambers.

On the other hand, .223-spec chambers have shorter throats (being designed for bolt guns and for accuracy), and while firing hot military 5.56 ammo will probably not be dangerous, the increased pressure commonly leads to feeding and extraction problems.

-Troy
4/10/2002 5:33:44 PM EDT
[#2]
A few weeks ago I wrote Bushmaster to ask them your exact question. They wrote back advising not to shoot 5.56 through .223, said all other combinations are ok.
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