Originally Posted By StagTodd:
But out of all seriousness what I was trying to show in my original picture /post, was that how easy it is for someone who was uneducated on what will work with what when referring to standard AR-15 rifles. When worked out "mathematically" with the numbers at hand (.226 and 5.56) when converting the .226 to metric you get 5.66mm which you would think is a bigger round then a 5.56.
With that information and that numbers don't lie, one would assume that the smaller bullet (5.56) could be fired out the bigger chamber (.223) with no problem. When switched obviously you cant load somthing bigger (.223) im something chambered for something smaller (5.56).
This is just the theory I had on why people thought you could shoot a 5.56 out of a .223 chambered rifle.
Does that make sense?
I suppose someone coming from outside the firearms world and was a math nut might arrive at that conclusion. Sound familiar ?
Those that have been around guns and especially those that have reloaded know that cartridge designers that were working on a particular bore diameter needed to clearly identify their caliber even though it uses the same bore diameter as many others.
There is a large family of cartridges that use .224 diameter pills (bullets).
Just a few....from memory.
.222 Remington Magnum
.224 Weatherby Magnum
They're simply names like Curly, Moe and Larry.....they don't necessarily represent actual diameters.
The .224 bore, as you can see, is very crowded and I haven't even listed the wildcat family.
The problem comes from someone erroneously thinking (or being told) that "5.56" is just the military designation for ".223" (which of course is false).
Knowing that the bullet diameters are the same only reinforces the thinking error.
It's the chamber difference (freebore region) that gets you. The .223 freebore is shorter and jamming a full power 5.56 in there will spike chamber pressures in the .223 chamber.