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Metal god · November 13, 2013, 12:35 PM

Do you have a link to the articles ? Couple things I'm noticing is all the charts above say 223 . As we know 223 does not have the same velocity as 5.56 . Did they test 5.56 loadings with the same 77gr and 80gr bullets . Just spit balling here but I would think you could get a 77 or 80gr bullet loaded to 5.56 specs to stabilize in a 1-12 twist better then the same bullets loaded to 223rem specs

Sooo , I wanted to make sure I was not wrong in my above statement/question . I went and looked at my Sierra book and now I'm more confused then ever . Comparing AR specs pg222 and 223 specs pg232 . How does the age old rule apply and be correct that 5.56 rounds are loaded to higher pressures then 223rem . Sierra is using all the same components for both loads and yet they load the 223 with heavier charges just about across the board .

More powder means more pressure , YES ? I also see the rounds really having the same velocity's if they were both shot from the same length barrel . The only difference I see is the twist rate . can or does the 1-7 create 10,000-ish more psi then a 1-12 and that's where the pressure difference between a 5.56 and the 223rem comes from ?

Every time I think I have a good understanding of something my reloading world gets turned upside down . I guess school is in session once again .

November 13, 2013, 12:35 PM	#8
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	Do you have a link to the articles ? Couple things I'm noticing is all the charts above say 223 . As we know 223 does not have the same velocity as 5.56 . Did they test 5.56 loadings with the same 77gr and 80gr bullets . Just spit balling here but I would think you could get a 77 or 80gr bullet loaded to 5.56 specs to stabilize in a 1-12 twist better then the same bullets loaded to 223rem specs Sooo , I wanted to make sure I was not wrong in my above statement/question . I went and looked at my Sierra book and now I'm more confused then ever . Comparing AR specs pg222 and 223 specs pg232 . How does the age old rule apply and be correct that 5.56 rounds are loaded to higher pressures then 223rem . Sierra is using all the same components for both loads and yet they load the 223 with heavier charges just about across the board . More powder means more pressure , YES ? I also see the rounds really having the same velocity's if they were both shot from the same length barrel . The only difference I see is the twist rate . can or does the 1-7 create 10,000-ish more psi then a 1-12 and that's where the pressure difference between a 5.56 and the 223rem comes from ? Every time I think I have a good understanding of something my reloading world gets turned upside down . I guess school is in session once again . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .