March 10, 2015, 10:16 PM | #1 |
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For 3006 , a factory case is 2.042 " from shoulder to base.
Why does a once fired case measure the Same ? When I go to full length size fired brass , will I need to set my die to put the shoulder back to 2.042 " from the shoulder to base when it begins to stretch ? Thanks ? |
March 10, 2015, 10:22 PM | #2 |
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I'm certainly no expert (and I'm sure one will come along shortly to give some better technical details) but what you are talking about is SAAMI spec for shoulder datum. If you are shooting an autoloader then bumping the shoulder back to that length is usually needed for the autoloader to feed correctly.
However, for a bolt action - you'll frequently hear about people just neck sizing. That is because they actually WANT their brass to stretch out. A chamber's size is seldom exactly SAAMI spec. It is usually longer. Letting the brass stretch out to better fit the chamber normally increases accuracy. Once you find out what the length of your particular chamber is, then you can set your dies to only bump the shoulder back to that particular length. |
March 10, 2015, 10:35 PM | #3 |
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OK thanks Doyle , I'm starting to get there ! And it is for a bolt action.
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March 10, 2015, 11:25 PM | #4 |
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I do not know where you got the 2.042 from ???
get out the loading book and check the dimensions ( most loading books have an picture with dimensions ) new factory cases will be way to small so it will go into any gun with that caliber chamber myself , I use a RCBS Precision Mic. one of the tools in that kit measures the case, I use it to adjust the sizing die a couple of thou. shorter than the chamber in the rifle I am sizing for |
March 11, 2015, 04:39 AM | #5 |
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The hornady handbook says 2.111.
Lyman 48 says 2.109 Speer 12 says 2.1086 Modern reloading says 2.109 |
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