308 Brass resized to 7mm-08?

billyc

billyc

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Resized a bunch of 308 Brass to 7mm-08. Went to trim and brass is shorter then my 7mm-08 brass. Didn't have to trim. Is this normal or am I doing something wrong when resizing.
My 7mm-08 brass trimmed is 2.030
The 308 brass resized is 2.003
 
I haven't resized to 7-08, but it sounds normal and should present no problem, whatsoever. It will just be longer before you have to trim them.
I have resized 30-06 to 270 and the 270 brass ends up about .100" shorter than regular 270 length. That makes no difference to the qulaity of the 270 brass, we just shoot them and eventually they will grow to size.
 
H4831 said:
I haven't resized to 7-08, but it sounds normal and should present no problem, whatsoever. It will just be longer before you have to trim them.
I have resized 30-06 to 270 and the 270 brass ends up about .100" shorter than regular 270 length. That makes no difference to the qulaity of the 270 brass, we just shoot them and eventually they will grow to size.
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No affect on accuracy then?
 
The necks of your .308 cases you resized to 7mm-08 will be thicker and your neck tension will be greater and you will have less neck clearance in the chamber. Both of these conditions can cause higher pressures than you had with your normal factory 7mm-08 cases.

Normally it isn't a problem but keep your eyes open to the difference, case neck thicknesses can be greater between brands of ammo so be advised.
 
H4831 said:
I haven't resized to 7-08, but it sounds normal and should present no problem, whatsoever. It will just be longer before you have to trim them.
I have resized 30-06 to 270 and the 270 brass ends up about .100" shorter than regular 270 length. That makes no difference to the qulaity of the 270 brass, we just shoot them and eventually they will grow to size.
Click to expand...

Done the same no problem. Any accuracy change was no doubt me not the cartridge or rifle. And like an idiot I sold the 270 .

Time to look at getting another.
 
Eye'll bite.........
Nosler Fifth Edition states for case overall length (coal) on the 308 is 2.015"
7mm-08 is 2.035"

I have two spent cases in the 308 one is 2.0105" coal
and when run through the 7mm-08 die is 2.0185"

Second 308 started at 2.009"
and through the 7mm-08 is 2.015"

Neck sizing from the 308 win to 7mm-08, the cases should realistically grow a bit.
Just did this little experiment out in the shop.
Please note that I am not an expert reloader, just doing it for myself and I should state that
this will not hold me responsible for others attempts or failures in reloading.
Regards.
 
There is no potential difference in accuracy due to a slightly shorter case than the specifications.
If you want to remove any variable, then trim all of your cases to the same length. It will not be the book length, but that doesn't matter. (It never does, other than a safety thing to ensure that you are not jamming the case into the throat).
 
You should work up a different load than what you had for your 7-08 cases the 308 cases may be a diferent weight most likely heavier [so more pressure if they are].
I did some 243 cases from 308 cases and they were much heavier than the 243 brass so I had to back off on the powder.
 
Case neck thickness can increase dramatically. I necked down some 308 to 7mm08 and the bullet pull was so high, when I went to pull the bullets and work on another loading, I could barely pull the bullets using a rock chucker and bullet pulling die. I literally lifted the top of the bench off the floor to pull them....so be VERY careful and mic your neck thickness, and start your loads on the light side and watch carefully for pressure signs.
 
I have used 308 brass to form 7mm-08 for years with no problem at all. If anything, the loads using brass formed from 308 cases are more accurate than factory 7mm-08 brass.

Paul, if you just seat the bullets a tad deeper to break the bond that develops between the case neck and the bullet before pulling them, they will pull quite easily. You can actually feel and hear the bullet break free in the case neck. This should be done before any bullet pulling operation.

Ted
 
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I use 308 win norma brand brass in my 260 and have no problems. Same thing as you it is shorter than my trim to length but it will grow. I haven't noticed any difference in neck tension, worked up my loads and love the new brass.
 
I always use .308 brass in my 708. I've found different makes of brass may or may not require trimming when resized. You'll be just fine using those casings.
 
Picked up some nice, shiny .308 nickel brass at the range. I like nickel brass so I ran them through my 7-08 full length die and shot them out of my 7mm-08 with no problems or changes in accuracy whatsoever.
Did I mention how shiny and Kewl they look? :p
 
This explains my Primer differences ive been experienceing with my Whelen.

I done load development with necked up .270 win cases.. an my new relaoded ammo is the once fired Whelen shells... primers went from flat to "popping out" (rounding outwards) in a sense...
will FPS be any different? i guess there is more/less pressure between the two..
Cheers
 
coyote said:
You should work up a different load than what you had for your 7-08 cases the 308 cases may be a diferent weight most likely heavier [so more pressure if they are].
I did some 243 cases from 308 cases and they were much heavier than the 243 brass so I had to back off on the powder.
Click to expand...



Thank you for the comment, I've never gotten down to the why?????
 
Gday, i measured the case neck thickness off a .270 (rem brass) case and a 35 whelen (rem case) brass an they turned up the same size exactly..

thats 270 resized to 35..

i also find the cases from 06/270 shorten as i resize
 
I went the other way, ran some .243 thru a .260 neck sizer then the 7-08. Couldn't get them to chamber even after FL sizing, lots of donut at the bottom of the neck. Glad I only tried 10, neck turning is a PITA.
 
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