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Trick for full length resizing of 7mm08, and all .308 donor cartridges.


The Hero of Canton

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So I discovered my hornady resizing die was leaving a 5 thousands bell on the base of my 7mm08 brass. It was the cause of unfired cases being hard to extract when making the weapon safe. 

 

The weapon is a Aero Precision AR10 on 7mm08. Barrel is an old school Green Mountain melonited med HB.  Groups are amazing, and its pure death to let the hammer fall on deer and pigs. 

 

Cases are a mix of ones Ive shot and 160 or so once fired cases aquired at venues.

 

Of 240 rounds I had 30 or so that had this slight bell after being processed with the hornady 7mm08 dies 

 

Not wanting to unload the cartriges, I got to thinking on how to fix this

 

The solution was my RCBS FL 30.06 resizing die with the depriming ram removed. It can host the entire cartridge without changing the seat. Rock chucker twin single stage presses. 

 

I simply lubed the base and sent the die down over the entire case. It reset the brass, and erased the slight bell.  Now all 240 cases are matching in their dimensions.

 

From now on all my new to me brass will get the hornady die for neck and sholder, and the full length girdle of that RCBS 30.06 die. 

 

Making perfect ammo requires imperfect fixes.

 

 

 

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Question: Did they chamber okay after?

 

Looks like I may need to get me a 30.06 sizing die. I noticed something similar years ago when I reloaded .308 for my Garand and my Remington. I have my Garand back and will be reloading for it soon. ;)

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On 2/25/2021 at 5:42 PM, The Hero of Canton said:

So I discovered my hornady resizing die was leaving a 5 thousands bell on the base of my 7mm08 brass. It was the cause of unfired cases being hard to extract when making the weapon safe. 

 

The weapon is a Aero Precision AR10 on 7mm08. Barrel is an old school Green Mountain melonited med HB.  Groups are amazing, and its pure death to let the hammer fall on deer and pigs. 

 

Cases are a mix of ones Ive shot and 160 or so once fired cases aquired at venues.

 

Of 240 rounds I had 30 or so that had this slight bell after being processed with the hornady 7mm08 dies 

 

Not wanting to unload the cartriges, I got to thinking on how to fix this

 

The solution was my RCBS FL 30.06 resizing die with the depriming ram removed. It can host the entire cartridge without changing the seat. Rock chucker twin single stage presses. 

 

I simply lubed the base and sent the die down over the entire case. It reset the brass, and erased the slight bell.  Now all 240 cases are matching in their dimensions.

 

From now on all my new to me brass will get the hornady die for neck and sholder, and the full length girdle of that RCBS 30.06 die. 

 

Making perfect ammo requires imperfect fixes.

 

 

 

 

The reason this works is because the base of a 30-06 is 6 thousandths smaller than the 7mm-08. Essentially you are making the case 0.006" smaller than SAAMI specification.

 

Either you have an improperly cut die that is not fully resizing the case or the shell holder is too thick. 

 

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Another little trick is to take a few thousandths off the shell holder. I once bought a pile of brass for next to nothing for my old '91 Argentine Mauser. Problem was whatever fired them must have had a slightly longer chamber than mine. Needed to bump the shoulder back even with FL sizing, many of them wouldn't chamber. Ground the shell holder down a tad and worked like a champ.

JHC

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15 minutes ago, Capt. James H. Callahan said:

Another little trick is to take a few thousandths off the shell holder. I once bought a pile of brass for next to nothing for my old '91 Argentine Mauser. Problem was whatever fired them must have had a slightly longer chamber than mine. Needed to bump the shoulder back even with FL sizing, many of them wouldn't chamber. Ground the shell holder down a tad and worked like a champ.

JHC

 

When my dad bought his first set of dies for reloading 243. The gunsmith he bought them from took a few thousandths off the base of the die so that they pushed the shoulder back just a tiny bit more. Also because the case is slightly tapered it also sized the entire case a tiny bit smaller. Made all the difference in the world when reloading for a semi-auto.

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Guy that taught me to reload used to do that, make his own SB sizer. I remembered that trick, figured it would to the same thing to work down the shellholder. And if perchance it didn't work shellholders are cheaper than dies! :P

JHC

 

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Good advice.

 

I NEED a hobby mill. Maybe i can use my diamond sharpener to pull material off my seat to make the hornady resizer bump the last of the case. Weekend projects.

 

But for now fixt. 

 

This pig was taken Sunday  with my canoe gun in .308... DPMS  and it is far less picky about case dimensions. It eats anything.

20210228_111334.jpg

20210228_122924.jpg

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