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.308 to .260?

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03 February 2011, 21:41
1/2moa@200
.308 to .260?
I just built a .260 and looking for good brass. looks like lapua wont be here till late next month. Meanwhile, I have a 5 gal bucket full of once fired Norma .308! My question to you guys is...What do I need to neck them down? Or is this the right way too go? have all this good brass and really don't want to pay that crazy price for new Norma .260! and Remmington brass is out of the question. Thanks for all the help guys youve allways helped when I needed it!

Thanks Troy!
03 February 2011, 22:22
D Humbarger
If you had a 7mm-08 die you could run the 308 in it first then in the 260 die & check neck thickness. you don't want thick necks to cause pressure spikes.



Doug Humbarger
NRA Life member
Tonkin Gulf Yacht Club 72'73.
Yankee Station

Try to look unimportant. Your enemy might be low on ammo.
03 February 2011, 22:30
1/2moa@200
I do have a 7mm08 die..whats to thick? and how to check that? This is my first time changing brass.. what tools do i need other than the .260 die and 7mm08? what about a .260 neck sizer?
03 February 2011, 22:52
butchloc
you may need to thin the necks. check the loading manual and it will give you the dimensions of the case. in forming 260's from 308s i've had to turn the necks on some brass and not on others
03 February 2011, 23:34
1/2moa@200
So where do I get this tool to turn the brass to the thickness? And thanks for the info so far guys.. So do you think its worth all this to do? and will the brass be good enough to shoot Fclass with!Im new to this formimg thing!
04 February 2011, 03:53
bja105
I asked a similar question last year, and found the responses very helpful.
http://forums.accuratereloadin...111056241#9111056241

I made mine running 308 brass into a 260 die, with no intermediate steps.


Jason
04 February 2011, 04:13
A7Dave
Get a tin of Redding's Imperial Die wax, it will make resizing easy on the neck and shoulder.


Dave
04 February 2011, 16:15
xausa
quote:
Originally posted by 1/2moa@200:
So where do I get this tool to turn the brass to the thickness?


My first 6.5X08 (the original .260 Remington) dates back to 1958. Back then, the only way to insure proper neck thickness was neck reaming, which could be done with either a Wilson case trimmer or a RCBS neck ream die. I tried both, and both work, but neither is as precise as neck turning.

Neck turning can be done with a simple hand held tool or with a more expensive and complicated neck turning device to be used with a drill press, or several other alternatives in between.

I use the Forster drill press set up and have found it very satisfactory for my long range shooting.

The most important thing to remember is ensuring proper neck clearance. A 6.5mm bullet must pass freely into the neck of a fired case for neck clearance to be adequate.
04 February 2011, 18:59
243winxb
Neck DiametersMaximum cartridge neck diameter of a loaded round.= .2970"
After full length resizing, using the expander to move any donut to the outside of the neck, a Lyman type Outside neck turning tool should work. Have done it with 308 to 243win. But not worth the trouble.
04 February 2011, 23:19
bartsche
quote:
Originally posted by bja105:
I made mine running 308 brass into a 260 die, with no intermediate steps.


X 2 tu2 Just measured neck wall thickness on .260s made from mil. .308 and commercial .308 and both were right at .0105" The commercial .260 measured .0100"
Roll EyesThe neck diameter of two reformed Mil..308s measures .295" . hope this helps. beer


Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
04 February 2011, 23:51
fredj338
I didn't have any luck necking down 308 cases to 6.5 in one pass, neck would fold. I could do it w/ a 7-08 die, then to 260, but it req'd neck turning in my 260ai. No issues necking up 243 Lapua though. Big Grin


LIFE IS NOT A SPECTATOR'S SPORT!
05 February 2011, 00:07
wasbeeman
Resize one and then load it up and shoot it. If a bullet will slide into the neck of the fired cartridge, you don't need to neck turn.


Aim for the exit hole
05 February 2011, 00:09
xausa
quote:
Originally posted by bartsche:
quote:
Originally posted by bja105:
I made mine running 308 brass into a 260 die, with no intermediate steps.


X 2 tu2 Just measured neck wall thickness on .260s made from mil. .308 and commercial .308 and both were right at .0105" The commercial .260 measured .0100"
Roll EyesThe neck diameter of two reformed Mil..308s measures .295" . hope this helps. beer


Something about this doesn't compute: .295" (neck diameter) minus .264" (bullet diameter) equals .031". .031" devided by 2 equals .0155", which is about what I would expect necked down military brass to have as neck thickness.

Were you using a tubing micrometer to measure neck thickness or a vernier caliper?

Using .010" neck thickness in a .297" chamber would mean neck clearance of .013, or .0065 on a side, which would hardly be conducive to accuracy and would result in excessive neck resizing. My 6.5X08 match cases have a neck thickness of .0125" +/- .0005", resulting in a .288/.290" neck diameter, and the chamber neck measures .293". I use .308 BR cases with small rifle primers for long range work.
06 February 2011, 06:24
1/2moa@200
Going to try and see what happens.. Thanks for the info! Will report back..