Case head separation due to FL resizing brass?

[Pointman]

l

I have the same problem with Hornady brass in 338 Win. It seems to be pretty thin brass.

I definitely second the problem with Hornaday brass. I had a partial separation after 3 reloads on some 338 LM brass. I don't use max loads. The otrher brass, HSM is still going strong. I do just "kiss" the should back so it's not really an FL sizing. I really like their projectiles their brass, Not so much.

 

[bob mclelland]

There was an article in the July, 2010, copy of Shooting Times by Allan Jones on
how to deal with this problem. Supposedly only works with new brass. If interested
let me know and I'll send you a copy. Essentially what Allan suggests is that
you expand the mouth of a 7mm RM with say an 8mm "tapered neck expander for case forming" and then using a 7mm RM neck sizing die start to build a small shoulder
on the expanded neck, testing in the rifle until it will chamber and head space on
this small shoulder. Then fire form and once fired brass will fit your chamber and
head space on the shoulder.

 

[trhall]

There was an article in the July, 2010, copy of Shooting Times by Allan Jones on
how to deal with this problem. Supposedly only works with new brass. If interested
let me know and I'll send you a copy. Essentially what Allan suggests is that
you expand the mouth of a 7mm RM with say an 8mm "tapered neck expander for case forming" and then using a 7mm RM neck sizing die start to build a small shoulder
on the expanded neck, testing in the rifle until it will chamber and head space on
this small shoulder. Then fire form and once fired brass will fit your chamber and
head space on the shoulder.

Seems easier just to get a good digital headspace gauge and verify everytime you set up your resizing die.

 

[MNbogboy]

Seems easier just to get a good digital headspace gauge and verify everytime you set up your resizing die.

That initial "false" shoulder on new brass will add additional life to the case by eliminating that first firing "stretch" caused by shorter base to shoulder measurement on new unfired cases.
The first firing of a case has a lot to do with its useful life. Primer pocket life can also be extended by not shooting full power loads when the brass is new, preferably for two or more firings. Frequent annealing will also provide for more accurate and consistent shoulder bumping.
My .02,
Randy

 

[trhall]

That initial "false" shoulder on new brass will add additional life to the case by eliminating that first firing "stretch" caused by shorter base to shoulder measurement on new unfired cases.
The first firing of a case has a lot to do with its useful life. Primer pocket life can also be extended by not shooting full power loads when the brass is new, preferably for two or more firings. Frequent annealing will also provide for more accurate and consistent shoulder bumping.
My .02,
Randy

Great info, thank you. I do anneal my cases after each 3rd firing.

 

[keithcandler]

Totally ignore the belt.

In the many 7 Mags I have had, I full length size. Neck sizing did not help accuracy.

I shoot warm loads, gun tells me what is the most accurate.

Remington and Winchester brass only, Winchester is tougher.

For each gun, I set a full length sizer to fit the chamber. In other words, with the case that is tight to close the bolt prior to sizing, I carefully screw the die down in 1/16-1/32 of a turn. I want the bolt to close with no resistance on sized brass that needed full length sizing prior to the sizing.

Two dimensions you are working with:

Bolt face to shoulder

Web diameter

In most full length sizing dies, you will have to push the shoulder back a substantial amount before the dimension at the web is sized down to where the bolt will easily close.....006 or MORE!

So, after 4-6 firings, you start to see a little ring form in front of the Belt....discard those cases...easy.

If you do happen to have a case head separation, usually it cracks and you get the entire case out of the rifle. If the forward part of the case sticks in the rifle, then a 38 or 45 caliber pistol brush inserted inside the case will easily remove the piece of brass.

It is difficult for manufactures to meet all requirements for all chambers, ON the two dimensions.

In a perfect world, you would have options:

a. separate die to size the web

b. separate die to push back the shoulder, and regular Forster neck sizing dies
will accomplish this.

c. custom die fit for your chamber that would be a be made off of a fully fire formed case that did not need full length sizing.

You hear a lot of talk about pushing back shoulders .001,.002 etc. Often when you push the shoulders back .002, the web has not been fully sized to where the case will allow the bolt to close easily. This is typical of factory chambers.

Custom guns can be different, but it will depend on how the reamer has been spec'd out.

Remember that standard Forster Neck sizers can bump shoulders on all cartridges that they make this die for. They also make Shoulder bump dies with different sizing bushings that are wonderful.

Often, you have the case where all you need is a shoulder bump.

 

[SealT5]

Let's keep some expectations in check. 3-5 firings with a hornady brass is acceptable. Brass is a consumable.

Joe S

 

[Vol1975]

Totally ignore the belt.

In the many 7 Mags I have had, I full length size. Neck sizing did not help accuracy.

I shoot warm loads, gun tells me what is the most accurate.

Remington and Winchester brass only, Winchester is tougher.

For each gun, I set a full length sizer to fit the chamber. In other words, with the case that is tight to close the bolt prior to sizing, I carefully screw the die down in 1/16-1/32 of a turn. I want the bolt to close with no resistance on sized brass that needed full length sizing prior to the sizing.

Two dimensions you are working with:

Bolt face to shoulder

Web diameter

In most full length sizing dies, you will have to push the shoulder back a substantial amount before the dimension at the web is sized down to where the bolt will easily close.....006 or MORE!

So, after 4-6 firings, you start to see a little ring form in front of the Belt....discard those cases...easy.

If you do happen to have a case head separation, usually it cracks and you get the entire case out of the rifle. If the forward part of the case sticks in the rifle, then a 38 or 45 caliber pistol brush inserted inside the case will easily remove the piece of brass.

It is difficult for manufactures to meet all requirements for all chambers, ON the two dimensions.

In a perfect world, you would have options:

a. separate die to size the web

b. separate die to push back the shoulder, and regular Forster neck sizing dies
will accomplish this.

c. custom die fit for your chamber that would be a be made off of a fully fire formed case that did not need full length sizing.

You hear a lot of talk about pushing back shoulders .001,.002 etc. Often when you push the shoulders back .002, the web has not been fully sized to where the case will allow the bolt to close easily. This is typical of factory chambers.

Custom guns can be different, but it will depend on how the reamer has been spec'd out.

Remember that standard Forster Neck sizers can bump shoulders on all cartridges that they make this die for. They also make Shoulder bump dies with different sizing bushings that are wonderful.

Often, you have the case where all you need is a shoulder bump.

Interesting. I do steps A and B for the most parts. The two times I have had this case head separation was when I tried to use the FL resize die to reduce everything back just enough for the bolt to close. Seems on the older brass and the way it pushes the brass back at the belt is where it stress the brass. Again this seems to happen when I done this on the older brass.

for the most part I've used the Forster neck die and the Willis belted magnum collet resizing die and been happy with results.

both guns I've had this happen was on custom barrels. Benchmark and Bartlein So I know everything was right. I've even checked everything with a go and no go Guage so I know it's all good on that aspects. Any way good post on your part.

Think going forward brass is cheap compared to the aspects of having a problem with one stuck in a chamber.

 

[keithcandler]

Die vs chamber dimensions causes short brass life. Remington 700's in 7 Mag shoot unbelievable, just watch the area in front of the web, as a ring starts to show up, throw the brass away....no big deal. I figure 5 firings, but you never know.

Many of the "most accurate" loads are .5g below being too hot, so pressures are up there. Primer pocket failure on Remington brand of brass is normal, and I throw away brass as needed. I de prime with a Neil Jones depriming tool, then hand prime with a RCBS or old Lee hand primer as a double check system for loose primer pockets.

Throwing away brass from loose primer pockets is probably 10x more prevalent than cases splitting from excessive sizing that is needed to reduce the web dia.

I had a Web sizing die, never used it in 5 years and sold it. I figured with a 7 STW and 7 Mag that I would be using the Web sizing die often, but never did.

 

[Sniper97]

Just had this happen yesterday in my 6.5-284 norma with Lapua brass. Don't know where I went wrong. Gun shoots lights out.

 

[Deleted member 107796]

Let's keep some expectations in check. 3-5 firings with a hornady brass is acceptable. Brass is a consumable.
Joe S

I'm loading for about 13 calibers and completely agree with this. I did not catch the number of times the OP's failed brass was reloaded, but I'm at about 4-5x max reload cycles for all of my brass.

 

[XTR]

Pushing the shoulder back is a big part of the problem. ....

fix.t

 

[Vol1975]

I'm loading for about 13 calibers and completely agree with this. I did not catch the number of times the OP's failed brass was reloaded, but I'm at about 4-5x max reload cycles for all of my brass.

the first time it happened it was on Remington brass and maybe 5 or 6 firings.

The most recent one was on federal brass and I was on my 4th firing. I was resizing the brass just enough to load in the gun but when I pulled tried to pull the brass out complete head separation. I count my self lucky because I feel sure it would have stuck in the gun. The brass was super thin where it pulled off.
On the other hand...
I've got some nosler brass thats on my 7th firing. The brass looks good but I'll be honest I'm going to file it away for war time. Little gun shy now on the brass after so many firing. Done set up and been slowly prepping new brass now. Man I hate the new brass prep. Just ain't taking the chance. I'm still trying to save my die by getting the brass out.

 

[MNbogboy]

Learning from my own goof ups over the years (54 years reloading) have found that there is always room for error.
Early on I followed die manufacturers instructions about kissing/cam over the shell holder to the sizing die. This works ok, for a while. If your chamber is short enough you may never experience trouble with incipient head separation. On the other hand using the die that way with a longer chamber may bump every case back excessively (.004 or more). New brass can be .008 or more. I have found best brass life in the .001 to .002 range.
Real care must be taken when setting bump. I used to keep snugging the die down till it measured correct from shoulder to base (compared to pre-sizing measurement). That case would be correct. The next case most likely would have been shortened way too much. The "springback" changes with each stroke after that initial compression/squeeze.
Have found that using a different piece of fired brass for each adjustment will get you to where you need to be. Even then every case should be measured individually during bumping. Fresh annealed brass bumps far easier and die should be set accordingly. Annealed brass lots require less tweaking during that process. Often one setting may get you through the whole lot (but not always). Brass brands most often require different settings even if annealed every time.
Hope my past mistakes help someone to develop their own method of proper consistent bumping.
Thinning brass can be detected with the "paperclip" test and often visually by a shiny ring part or all around the case just ahead of the web. I built a tool by reforming a screw driver blade to work like the "paperclip". If you see the "ring" you will feel the thinning of the case with the tool. Tool is now seldom used with proper annealing & bumping.
Side note: my first head separation cost me a nice buck in WI back in the early 70s. Missed him on the run and then he stopped at 50 yards.........couldnt chamber the next round.
Randy