.308 Win / 7.62 NATO case trim length

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dodpilot
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.308 Win / 7.62 NATO case trim length

Post by dodpilot »

Question: For .308 Win / 7.62 NATO, what is the absolute min case trim length? I have ~ 500 pieces of OFB Lake City 7.62 NATO Long Range (LR), and the cases measure 2.008 to 2.015. I want to weigh, sort and cull the cases this week. Obviously, if the cases aren't all the same OAL, weighing them is a waste of time. So, ... Is it excessive to trim down OAL to the shortest in the batch and therefore make all cases that short (2.008")?
My reloading manual states max trim length = 2.015", but does not list a min case trim length.
Thoughts?

- CS
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Netpackrat
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Re: .308 Win / 7.62 NATO case trim length

Post by Netpackrat »

It should also list a "trim to" length. The max trim length is just that... The maximum they can stretch to before you have to trim them again.
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First Shirt
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Re: .308 Win / 7.62 NATO case trim length

Post by First Shirt »

The Hornady book shows a trim length of 2.005 inches, and a max of 2.015 inches.
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
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Weetabix
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Re: .308 Win / 7.62 NATO case trim length

Post by Weetabix »

What all information does one get from weighing cases?
Note to self: start reading sig lines. They're actually quite amusing. :D
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First Shirt
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Re: .308 Win / 7.62 NATO case trim length

Post by First Shirt »

You get an idea of the uniformity of the cases in a batch. If they weigh the same, after trimming, they should all have the same internal capacity, which will result in consistent pressures, thus, consistent velocities. The fewer variables you have in reloading the more accurate your loads are.

Also, if they weigh the same, the neck and wall thickness is probably the same, or extremely close. Neck thickness will affect how tightly the case grips the bullet, which also has an affect on pressure, and thus, accuracy.
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six."
Lindy Cooper Wisdom
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Weetabix
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Re: .308 Win / 7.62 NATO case trim length

Post by Weetabix »

Does consistency have something to do with accuracy? :P

(j/k :D )
Note to self: start reading sig lines. They're actually quite amusing. :D
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