Excessive headspace on virgin brass

[TackDriver284]

Checked headspace on virgin Norma brass for the 300 Win Mag and it shows 2.256" and the fired Norma is 2.273", that is .017" headspace. Geez
Is there an advice to this,,,,possibly just .005" jam in with Ballistic Tips and use low to mid charges to blow out the front shoulder to 2.253" instead of off the lands where it may slam the casehead back on the boltface?

 

[NYDAN]

Mark,
I have found that 0.017" headspace to be quite common with the Norma cases in the belted magnums such as the 300 Win Mag. and the 7mm Rem. Mag.

I have followed Scotty's recommendation of making a false shoulder by necking up with a 8mm expander and then sizing back to 30 caliber only part of the neck so the 8mm expanded part jams at the chamber's shoulder/neck intersection. This procedure is supposed to minimize the thinning of the case in front of the case head (to prevent potential future case head separation). Somewhere in the forum is a detailed description and drawings of how to do this. If you can't/don't find the thread I can do a more detailed explanation.

 

[RL338]

This is why Peterson offers their long version of 300 WM brass.

 

[TackDriver284]

Mark,
I have found that 0.017" headspace to be quite common with the Norma cases in the belted magnums such as the 300 Win Mag. and the 7mm Rem. Mag.

I have followed Scotty's recommendation of making a false shoulder by necking up with a 8mm expander and then sizing back to 30 caliber only part of the neck so the 8mm expanded part jams at the chamber's shoulder/neck intersection. This procedure is supposed to minimize the thinning of the case in front of the case head (to prevent potential future case head separation). Somewhere in the forum is a detailed description and drawings of how to do this. If you can't/don't find the thread I can do a more detailed explanation.

I do remember that post. Checked and found the post.

300 Win Mag brass

My current Norma brass for the 300 Mag has been fired at least 4 to 5 times, and on the last loading I did feel some slightly loose primer pockets. I'm lurking around for better brass if any, what do you guys think about Petersons or Lapua brass? I have had great results with Lapua brass in...

forum.nosler.com

 

[SJB358]

Dan beat me to it. I false shoulder just about everything just to control headspace from the first firing.

 

[clearwater]

What's the point of the belt then?

This also might explain some crushed shoulders when my friend tried resizing once fired brass from another gun.

 

[SJB358]

What's the point of the belt then?

This also might explain some crushed shoulders when my friend tried resizing once fired brass from another gun.

There is no point…. In a sharp shouldered case the belt is there because we used the H&H to make everything back when all these cartridges were developed.

 

[PJGunner]

What's the point of the belt then?

This also might explain some crushed shoulders when my friend tried resizing once fired brass from another gun.

The belt is supposed to provide proper hedspacing of the cartridge, However, it doesn't even come close most of the time, if ever. About the only solution(s) are enlarging the neck, then sizing properly to create a shoulder or charges of fast powder with a wax plug in the neck for a bullet. Then one can properly set up the sizing die so that the brass headspaces on the shoulder where it belongs.
Paul B.

 

[desertcj]

The belt is supposed to provide proper hedspacing of the cartridge, However, it doesn't even come close most of the time, if ever. About the only solution(s) are enlarging the neck, then sizing properly to create a shoulder or charges of fast powder with a wax plug in the neck for a bullet. Then one can properly set up the sizing die so that the brass headspaces on the shoulder where it belongs.
Paul B.

You know that the headspace gauges don’t even have shoulders on them right? Yes, that allows the shoulder to possibly blow forward until it hits the shoulder in the chamber. The false “neck shoulder” helps and so would fire forming with a bullet lightly jammed into the lands. The guys that full length size belted magnums have the most issues with the belt IMO. I neck size only and I have zero issues with the belt.

 

[SJB358]

Never had a wisp of trouble with a belted case. Just doesn’t even matter to me in the grand scheme.

 

[RL338]

Back in the day the belt on a cartridge made you a tough guy. “I shootin’ a magnum , whatcha you got” that’s what the belt is for.
I treat my belted brass the same as unbelted 0.002” shoulder bump.

 

[jimbires]

also ,
the belt sets the "headspace " between the brass case and the bolt face . I'm not sure if "headspace" is the correct term for this . so the brass can be fireformed into whatever . once the brass is fired , you are much better off forgetting the belt . just size the brass to fit the chamber .