Brass Separation Above Belt

[curtiscd]

I have a buddy that had a re-barrel done recently on a 338 Win. He shot a box of Hornady Precision Hunter ammo with 230 Eld-X's through it for break in. He then FL sized and loaded the same brass with same bullet and a mild charge. He shot 6 rounds and each one was beginning to separate just above the belt. Out of curiosity he found a piece of Rem. brass and loaded it up with an even milder charge and the results were the same. What would be the cause of this issue? Is it possible that it's an issue with head spacing?

 

[CatShooter]

I have a buddy that had a re-barrel done recently on a 338 Win. He shot a box of Hornady Precision Hunter ammo with 230 Eld-X's through it for break in. He then FL sized and loaded the same brass with same bullet and a mild charge. He shot 6 rounds and each one was beginning to separate just above the belt. Out of curiosity he found a piece of Rem. brass and loaded it up with an even milder charge and the results were the same. What would be the cause of this issue? Is it possible that it's an issue with head spacing?

Yes... he is pushing the shoulder back when he FL sizes. When adjusting a FL die for ANY cartridge (especially a belted case) the die must be set so it does not push the shoulder back.

The case should be sized so you feel a light resistance when the bolt handle goes down.

 

[Mike Thorn]

Get a Wilson adjustable case gauge and use that with a fireformed case to set the die. I'm reloading .460wby, trying to get as much brass life as possible.

 

[memtb]

I'm guessing excessive headspace! And, full length resizing is exasperating the situation. Even then,separation with only one reloading seems extreme. memtb

 

[Rich Coyle]

Often I read here that one should make sure there is hard contact between the sizer and the shell holder. That certainly is not my method. I size cases only until they barely fit the chamber.

The cases you're talking about have shoulders pushed back too far.

 

[Barrelnut]

I agree that it's a possible headspace issue. One FL resize that sets the shoulder back to standard dimensions after one firing of new brass, should not cause a head separation situation. I've loaded a lot of 7RM before and set the shoulder all the way back and not had one start to separate on the second firing.

I suggest using Hornady Comparator gauge set and measure the length of a new unfired case at the shoulder datum. Then measure it after firing the case. I think if it is more than .008 or so, that could be a problem. And may be why it is starting to seperate on the second firing. You need the comparator to tell you what is going on.

It is typical for belted magnum cases to stretch quite a bit on first firing, This is by design. They may not even reach full chamber dimensions on the first firing, It may take three firings and just neck sizing before it get hard to chamber before it is time to bump them back .002. that's the way I do with my 7RM.

 

[CatShooter]

I agree that it's a possible headspace issue. One FL resize that sets the shoulder back to standard dimensions after one firing of new brass, should not cause a head separation situation. I've loaded a lot of 7RM before and set the shoulder all the way back and not had one start to separate on the second firing.

I suggest using Hornady Comparator gauge set and measure the length of a new unfired case at the shoulder datum. Then measure it after firing the case. I think if it is more than .008 or so, that could be a problem. And may be why it is starting to seperate on the second firing. You need the comparator to tell you what is going on.

It is typical for belted magnum cases to stretch quite a bit on first firing, This is by design. They may not even reach full chamber dimensions on the first firing, It may take three firings and just neck sizing before it get hard to chamber before it is time to bump them back .002. that's the way I do with my 7RM.

I have a 264 Win Mag that has 0.007" belt headspace, and 0.036" (yup, 36 thou) shoulder headspace.
When I fire a new case, the shoulder blows forward from 32 to 36 thou. If I push that shoulder back, and shoot it again, I will get 2 or 3 reloads before it separates.

Soooo... I oil the case with very light oil (G-96), and fire the case - the oil allows the whole case to slip back without ANY stretch at all.
Then I neck size with a Bushing "S" die, and shoot the case again, etc.
IF, the case reaches the point that bolt closing is more difficult than I am willing to live with, I will use a Body die to move the shoulder back 0.001" at a time, until there is still bolt closure resistance, but I can live with it - set up that way, the cases last forever..

 

[Rich Coyle]

Good post, CatShooter.

 

[CatShooter]

Thank you...

 

[just country]

morning, good post catshooter. doesn't the maker of the brass
have an adverse effect on the stretch of the brass. some brass
has a different hardness which could more or less stretch.
myself I like Winchester, Lapua and Norma brass if possible.
GBOT TUM

 

[CatShooter]

morning, good post catshooter. doesn't the maker of the brass
have an adverse effect on the stretch of the brass. some brass
has a different hardness which could more or less stretch.
myself I like Winchester, Lapua and Norma brass if possible.
GBOT TUM

Yes... A while back, I ran hardness tests on brass...

http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/

... and I found that REAL Lake City, Lapua, Norma, and Winchester were at the top of the food chain as far as hardness goes. Rem was down there and Hornady (which was not published in this report) was at the bottom of the bird cage

 

[Scooterbum]

I have a 264 Win Mag that has 0.007" belt headspace, and 0.036" (yup, 36 thou) shoulder headspace.
When I fire a new case, the shoulder blows forward from 32 to 36 thou. If I push that shoulder back, and shoot it again, I will get 2 or 3 reloads before it separates.

Soooo... I oil the case with very light oil (G-96), and fire the case - the oil allows the whole case to slip back without ANY stretch at all.
Then I neck size with a Bushing "S" die, and shoot the case again, etc.
IF, the case reaches the point that bolt closing is more difficult than I am willing to live with, I will use a Body die to move the shoulder back 0.001" at a time, until there is still bolt closure resistance, but I can live with it - set up that way, the cases last forever..

I would setback the barrel to compliment the f.l. die. Finis.

 

[L.Sherm]

I would check the headspace before Idid anything. If you have to rent a set from 4D reamer rentals, it would be about 20.00. If the headspace is correct then I would get get some better brass and not bump the shoulders back so far. Setting the barrel back to match the dies is not fixing the problem. There is nothing wrong with FL sizing done properly.

 

[CatShooter]

I would setback the barrel to compliment the f.l. die. Finis.

That makes no sense - it would require a custom reamer and custom die. To what end - there is no problem.