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Rifles, Reloading, Optics, Equipment
Reloading
reloading for 223/5.56 questions
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<blockquote data-quote="bigedp51" data-source="post: 1144598" data-attributes="member: 28965"><p>Both the .223 and 5.56 are loaded to the same exact chamber pressure of 52,000 cup or 55,000 psi. The pressure confusion comes from where the pressure traducer is located for the European CIP (NATO) pressure readings and reads as 62,000 psi.</p><p></p><p>Below the specifications for the M855 5.56 round. (55,000 psi SAAMI transducer method)</p><p></p><p><img src="http://i122.photobucket.com/albums/o254/bigedp51/PagesfromTM43-0001-27_CHG-2a_zps8ca7aaa4.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /> </p><p></p><p>The SAAMI interchangeability pressure warning between the .223 and 5.56 came out in approximately 1979 when the military switched from the M193 round to the M855 round and lengthened the throats on the M16 rifles.</p><p></p><p> <img src="http://i122.photobucket.com/albums/o254/bigedp51/223_zps6248614d.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p>The problem is when the military M855 round is fired in the shorter SAAMI .223 throat the the chamber pressure will be approximately 5,000 psi higher.</p><p></p><p>Now to add even more confusion, the throat in my Savage .223 with a 1 in 9 twist is longer than the throat in my AR15 rifles. Many of the rifle manufactures today are making the .223 chambers with a longer throat. This makes plenty of room in the chamber for the cartridge and the company lawyer and also lowers the chamber pressure.</p><p></p><p>Also note that military brass like Lake City is made harder in the base than any commercial .223 case. Meaning Lake City brass is the best brass the American tax payers can buy.</p><p></p><p> <img src="http://i122.photobucket.com/albums/o254/bigedp51/556hard-a_zps7570e6b0.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p><img src="http://i122.photobucket.com/albums/o254/bigedp51/hardness-a_zps8d54ad66.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p>The 5.56 cases were made harder to help prevent the jamming problems the early M16 rifles had.</p><p></p><p><img src="http://i122.photobucket.com/albums/o254/bigedp51/Casehardness-a_zps14dbe0fd.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p><p></p><p></p><p><img src="http://i122.photobucket.com/albums/o254/bigedp51/blackrifle_zpsdc047115.jpg" alt="" class="fr-fic fr-dii fr-draggable " style="" /></p></blockquote><p></p>
[QUOTE="bigedp51, post: 1144598, member: 28965"] Both the .223 and 5.56 are loaded to the same exact chamber pressure of 52,000 cup or 55,000 psi. The pressure confusion comes from where the pressure traducer is located for the European CIP (NATO) pressure readings and reads as 62,000 psi. Below the specifications for the M855 5.56 round. (55,000 psi SAAMI transducer method) [IMG]http://i122.photobucket.com/albums/o254/bigedp51/PagesfromTM43-0001-27_CHG-2a_zps8ca7aaa4.jpg[/IMG] The SAAMI interchangeability pressure warning between the .223 and 5.56 came out in approximately 1979 when the military switched from the M193 round to the M855 round and lengthened the throats on the M16 rifles. [IMG]http://i122.photobucket.com/albums/o254/bigedp51/223_zps6248614d.jpg[/IMG] The problem is when the military M855 round is fired in the shorter SAAMI .223 throat the the chamber pressure will be approximately 5,000 psi higher. Now to add even more confusion, the throat in my Savage .223 with a 1 in 9 twist is longer than the throat in my AR15 rifles. Many of the rifle manufactures today are making the .223 chambers with a longer throat. This makes plenty of room in the chamber for the cartridge and the company lawyer and also lowers the chamber pressure. Also note that military brass like Lake City is made harder in the base than any commercial .223 case. Meaning Lake City brass is the best brass the American tax payers can buy. [IMG]http://i122.photobucket.com/albums/o254/bigedp51/556hard-a_zps7570e6b0.jpg[/IMG] [IMG]http://i122.photobucket.com/albums/o254/bigedp51/hardness-a_zps8d54ad66.jpg[/IMG] The 5.56 cases were made harder to help prevent the jamming problems the early M16 rifles had. [IMG]http://i122.photobucket.com/albums/o254/bigedp51/Casehardness-a_zps14dbe0fd.jpg[/IMG] [IMG]http://i122.photobucket.com/albums/o254/bigedp51/blackrifle_zpsdc047115.jpg[/IMG] [/QUOTE]
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reloading for 223/5.56 questions
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