First attempt at necking down 308 to 7mm08
Well guys I had a go at this and didn't have any luck.
I got a few bits of that 308 brass I've got, put a tiny bit of lube on them, and slowly pushed it into the pull length 7mm08 sizing die.
I couldn't close the bolt on my rifle with any of the necked down cases. I also noted the necked down cases are a little bit shorter than the length I normally trim too. Not being able to close the bolt is a little concerning though and I didn't want to force it obviously.
I measured the outside neck diameter of the cases:
Once fired, fully prepped 708 case:
Outer width: 7.81mm
Neck width: 0.31
Once fired, fully prepped 308 military case #1:
Outer width: 7.96mm
Neck width: 0.41
Once fired, fully prepped 308 military case #2:
Outer width: 7.99mm
Neck width: 0.44
Once fired, fully prepped 308 military case #3:
Outer width: 7.94mm
Neck width: 0.41
It's a bit weird the necked down cases are wider.
You can see the actual necks are visibly thicker on the necked down cases (to be expected I imagine... probably need to be reamed out from what I hear).
http://i1222.photobucket.com/albums/...psb42ba969.jpg
And you can see the shoulder isn't quite right (necked down case is on the left)
http://i1222.photobucket.com/albums/...psd0db4bc1.jpg
http://i1222.photobucket.com/albums/...ps072daae6.jpg
You can tell the third case is the 7mm08 one
http://i1222.photobucket.com/albums/...ps2f91e4f4.jpg
Where am I going wrong chaps?
Re: First attempt at necking down 308 to 7mm08
I suspect you need to adjust your die down to compensate for the extra force required to size down.
Give one the vivid treatment and try to chamber to see where its hitting. Could be neck but more likely shoulder or body
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Re: First attempt at necking down 308 to 7mm08
Really need to do the vivid test to check body. Military arms can have large chambers and may need a body or small base die to get it back in size. Or if lucky and carefull may get away with it with standard fl die .
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