FL vs neck resizing

[mljdeckard]

Ok, so, I have been learning and doing a lot of case prep. One of my projects is my dad's old Remington 760 in 257 Roberts. I have the dies, and I have been sizing the brass I have.

I recall, maybe 25 years ago, my dad got some handloaded ammo from a friend and tried to use it, and the bolt wouldn't close on it all the way. He told me it had something to do with how it was loaded, and he got rid of it.

So now, my obvious concern is, how do I not make the same mistake? I am thinking that whomever loaded for it before was only neck sizing, and the rounds were too tight in the chamber, and it couldn't close and lock completely. OR, it was old brass that needed to be trimmed, and they hadn't done it. So, I'm thinking, as long as I make sure the brass is the right length or .002" shorter, and I am careful with the OAL, and I am FL resizing, it should be fine, right?

 

[whubbard]

You should be fine. As far as I know you should only neck resize when you plan to fire the brass from the exact same rifle. Generally it will also be more accurate as the brass is perfectly fit to the chamber. So once you've fired it out of the 760, feel free to neck resize and trim.

 

[788Ham]

What has been told you is correct, in that firing from YOUR rifle, only neck sizing will be needed. My Pop reloaded for 2 different .243's, one a Savage lever, and the other a Remington bolt. After 3 or 4 reloadings, there were some rounds that wouldn't fit the lever, action wouldn't close. He was only necksizing. So, long story short, he had to keep cases separate for each rifle when reloading, marking boxes of ammo for each. Hope this helps! AND, after about 4 or 5 reloadings, you'll need to FL resize the cases, just to keep the brass from any heavy stretching!

 

[mljdeckard]

But even for a pump with a rotating bolt? I would think that it needs FL resizing for the same reason as an auto, the locking and extraction isn't as solid as a bolt rifle.

 

[kingmt]

I wouldn't NS for a pump rifle. Try to bump the shoulder back .002".

 

[earplug]

Small Base die for some rifles

Certain rifle actions don't have the powerfull closing action of a typical bolt gun.
Or the action/bolt flex's that allows the brass to stretch.
Its not a hard or fast rule on what loads and actions need the full length sizing and what will work with only neck sizing.
My common rifle that needs full length sizing with a small base die is my Savage 99 in 300 Savage.

 

[243winxb]

Ammo thatis full length resized will always chamber if sized correctly. Neck sizing is not recommended for Autos, pumps or lever actions. But neck sizing can & does work. Starting loads produce low pressure & do not expand the brass a lot. This is why the Lee Classic "hammer" Loader works with rifles when only neck sizing. Soon or later, you do have to FL size.

 

[NCsmitty]

You will need to FL size your brass with a standard FL die set, to consistently fit your Rem 760. They do not have the camming power of a bolt action, as you alluded to in your #4 post.
Set your die down until the empty sized brass just fits the chamber easily. The M760 can handle the +P loads listed for the 257 bob.
That's a wonderful rifle to have.


NCsmitty

 

[marcclarke]

But even for a pump with a rotating bolt? I would think that it needs FL resizing for the same reason as an auto, the locking and extraction isn't as solid as a bolt rifle.

Correct. You need to FL resize for a pump-action rifle.