Anyone neck size brass for a pump action?

07blackwater

07blackwater

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My 1954 model 760 270 seems to have a generous chamber.

I'm using federal brass at the moment because I have a good supply saved up and after 4 mild reloads the brass is done. I full length sizing each time and it gets really thin above the web with an obvious bulge.

I measured a factory load before and after and the Web diameter increased by 0.003", my handloads are the same. I'm guessing the gun simply has a big chamber.

What I'm wondering, has anyone had success neck sizing for a pump gun? I'd like to get more life from the brass. I'm only using 53 grains of IMR 4831 with a 130 grain pill so I'm not working it too hard by any means.
 
The other option is to partially resize with your FL die. This may be advantageous over neck sizing which allows the brass body to swell progressively between sizings - causing your brass to stick in the chamber at some point.
 
I have always FL resized my 270win brass for an identical gun because despite certain advantages in a pump gun, extracting tight cases is a weak point. I also reload for three other 270win for people I know and given that all only need to be minute of deer, there is no incentive to be particular.

More relative to answering your question: I always slide an empty into the chamber for releasing the tension on the firing pin for storing, a case that was fired from the gun and very rarely have I had trouble extracting the case with a rack of the slide BUT, there have been cases that require a bunt on the end of the forestock with the bottom of a fist, and even more if the case was previously fired in another rifle. I expect if you are using the brass through the same rifle, if it enters the chamber fine, can it really get tighter in the same chamber than it did after previous shot? It's something I haven't done, but if I wanted to be particular, I would undertake many trial tests for consistency before depending on it in a situation I might need a second shot.
 
I use a Rem. 7600 with neck-sized brass. I full length size if not fired first in my gun, then neck size only after that. I've only had a problem extracting once, and that was head separation due to a many-times fired brass.
Run a few fire formed cases through your gun, if they don't stick, I'd recommend neck sizing only.
 
Thanks for the input fellas.

I read that one guy had extraction issues out of his 760 after neck sizing only but that was after 4 loads.

What I'll do is set aside a dozen pieces of brass and partial full length size them with various charges (since I don't have a neck die yet) and see if I have issues.

What brass are you guys using?
 
You can neck size only by backing out your sizer/deprimer a bit. Can't remember how much, but maybe a half turn or so....
 
After I got out of the service in 1973 I bought a 760 Gamemaster in .270 and a Lee Loader that only necked sized. The third time I fired these cases they stuck in the chamber until the brass cooled down. The next day I bought a RCBS Rock Chucker press and started full length resizing all my pump action ammunition.

The 760 is not a bolt gun and doesn't have any primary extraction like a bolt action does, on a bolt action when you lift the bolt this moves the case slightly to the rear and breaks its grip of the chamber walls. I will guarantee you will get stuck cases because the brass is a form fit to your chamber and can't spring back to smaller size as they would if the cases are full length sized.

You "ALWAYS" full length resize pump actions and auto-loaders for this very reason, these type rifles do not have a strong primary extraction. A auto loader will rip the rim off a neck sized case and a pump action will need to wait for the cases to cool or even remove with a cleaning rod.

Neck sized practice ammunition is one thing, but hunting dangerous game is something else altogether.

And when all else fails read your reloading manuals where this very warning is written.
 
Try this:

take a 270 round fired in a different rifle and verify it will not chamber properly. Then back out your FL sizer 2 turns and size the case. Gently try to chamber it. If there is still resistance, turn the die in a half turn and try again. Once it chambers easily, turn the die in another half turn for insurance and lock the die ion that position. You are now sizing the brass enough to chamber, but no more. That might help extend brass life.
 
Ganderite said:
Try this:

take a 270 round fired in a different rifle and verify it will not chamber properly. Then back out your FL sizer 2 turns and size the case. Gently try to chamber it. If there is still resistance, turn the die in a half turn and try again. Once it chambers easily, turn the die in another half turn for insurance and lock the die ion that position. You are now sizing the brass enough to chamber, but no more. That might help extend brass life.
Click to expand...

Sounds like a good idea. The only problem I can see is it might be hard to find a rifle with a looser chamber than this one, it seems big. I've read that some think this is intentional to aid in extraction.
 
Yes, I understand the big chamber issue. A fatter case will help you calculate the best die position.


Backing out the die a rev might be a help. If you can't find the fatter case, just do that. On many of my rifles, I routinely do not FL the entire case. But they are all bolt actions.
 
So I did a little experimenting and found my once fired brass is a little tough to chamber.

Using some brass I'd planned on scrapping due to thinning at the web I proceeded to set my FL die to partial full length size. I think I've got it right with 0.014" gap between the shell holder and die. I realize every rifle will be different but does that sound about right?

I have a quite a few loaded to burn off before I resize anything I'm going to reload but the brass I partial sized loads and unloads fine but locks up nice and snug. Not forcefully, just snug.

One more thing, my handloads are relatively light in this rifle so I hopefully don't see extraction issues . I guess I'm just going to have to try a few and see.
 
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