Author Topic: .308 reloading question  (Read 2702 times)

Offline TooMuchGlass

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.308 reloading question
« on: July 07, 2014, 04:33:41 PM »
Hey all,

I've reloaded several different pistol cartridges safely and effectively (.38, .40, .45) and I'd like that trend to continue into my rifle cartridges. I've loaded .270 with supervision before, but now I'd like to do some .308. Here's my situation:

I have some deprimed .308 that fits in my chamber and measures up to the numbers in my Lee reloading manual. My question arises in the inside diameter of the neck though: the cases are .300" to .301". I don't want to run this brass through my full length sizing die if that ID will work, but I don't want to cram bullets either. I can't find the ID measurements anywhere online either.

I'll be using 168 gr. match kings in both a bolt action and an autoloader.

Thanks guys.

Offline NWPilgrim

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Re: .308 reloading question
« Reply #1 on: July 07, 2014, 05:03:50 PM »
Typically you need the case neck to be undersized from the bullet diamter by about .003" of inch for proper neck tension on the bullet.  The .30 caliber bullets are .308" diameter so you want the neck inside diameter to be NO MORE than .305". You can probably cram the bullets in but you might slightly deform them or loosen the lead core (not much elasticity) within the jacket (fairly elastic metal). The neck will probably give away sooner than the lead core will be crushed so it may be fine. If this is just plinking ammo I would load as is, but for precision work I would neck size them (assuming you are using a bolt action).

Offline Jack Crabb

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Re: .308 reloading question
« Reply #2 on: July 07, 2014, 08:49:58 PM »
You could run the sizer die up and only have the expander ball resize the internal diameter of the neck without sizing the case body.

Be careful with minimal resizing in an autoloader. One can get away with neck sizing or similar minimal resizing for a bolt action because one has the added leverage of the bolt to cram an oversize round and positively close the action. Autoloaders don't have that ability and an out of battery shot can be bad news.

Offline Mortblanc

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Re: .308 reloading question
« Reply #3 on: July 08, 2014, 08:14:00 AM »
Loading for a bolt gun and loading for an autoloader are two separate and disassociated activities.

Autoloaders often require full length resizing for every refill and a tight neck or even a crimp to hold the bullet in place while cycling through the action.

My bolt gun reloads get just enough sizing to hold the bullet in place while chambering. 

Some of my single shot reloads go unsized and you can pull the bullets with only finger pressure.

If you load for the autoloader you can use them in any of your rifles.


Almost every gun has a "favorite load" so you still have two different guns to work with and two loads to build.

I find that my .308 rifles are very finicky about their preferences.  One of my rifles shoots its favorite load into 3/8"@100 but it will not keep factory loads inside 6" at that range.  In turn, my autoloader will shoot any old milsurp or factory ammo I throw at it into 2"@100.

Offline DrJohn

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Re: .308 reloading question
« Reply #4 on: July 08, 2014, 08:47:28 AM »
I reload everything as if it is going to be used in an autoloader, as I have both bolts and autoloader varieties of the guns I reload for.