Case Head Separation

[Harv6]

I'm getting ready to reload some 7mm Remington Magnum brass from Winchester. I always full length resize and trim it down with a Lee case length gage and cutter. I've probably loaded each piece about 5 times now, with a load that's more like a maxed out 280 Remington. I did the paper clip test for the first time today and felt nothing but a smooth contour. I was kind of surprised that I didn't feel anything in terms of a groove. Is this normal? I know its varies on how hot you load it, but I figured it would be able to feel something by now.

 

[ksubuck]

You are full length resizing or just bumping the shoulder a couple of thousandths using a full length die?

I used to full length size every time and would get 3 to 5 loads before seeing too much stretch in cases

 

[ksubuck]

Mostly feel a contour but picked up a ridge on occasion. Retired the cases as soon as I felt anything.

 

[SJB358]

I've loaded all my belted magnums upwards of 15 times without having a separation. As long as your just minimally bumping the shoulder the cases will wear out in other ways before a CHS.

 

[Harv6]

The directions for the Lee FL sizing die say to screw it in to touch the shell holder, then 1/4 to 1/3 of a turn more. I do 1/4 turn.

 

[HeathSexton]

I always size my belted cases like nonbelted cases, I just bump the shoulders back .0015-.002" and I get 12+ loadings from them.


Following the directions they send with the dies is a good way to overwork your brass and shorten case life.

 

[Darkhorse]

My WW 7mm Mag. cases are old. And I get loose primer pockets before I get noticable case stretch. I Full Length size these cases and I screw my sizing die in until it just contacts the shell holder, no more. Then I size a few cases and try them in my rifle to see if they chamber. If so, I'll size several more and test them. If any don't chamber I'll just turn the die in about 1/8 turn and repeat the process.
Point is, I want my brass to fit my chamber with the minimum of shoulder set back. Instead of a headspace gauge I use my rifles chamber.
Now to contrast that let's consider my .300 Win. Mag. It has been about 10 years since I've done any serious loading for it. And then it was mostly Neck Sized only so I didn't notice any problems. But last year I noticed CH separation on several cases. What I use to do was follow the die makers recommendations and turn that die in a 1/2 turn or so after contact with the shell holder. That was all it took to set the shoulder back enough to ruin a case after only a couple of firings.
Belted magnums are the worst when it comes case to stretch from sizing.

 

[SJB358]

I always size my belted cases like nonbelted cases, I just bump the shoulders back .0015-.002" and I get 12+ loadings from them.


Following the directions they send with the dies is a good way to overwork your brass and shorten case life.

Heath is spot on. No reason to size the cases that far. An easy way to check them and be relatively close is to pull your firing pin, smoke the cases and barely size them to the bottom of the neck. Try to chamber, if there is too much resistance turn the die down about an 1/8. Size again. That will get you relatively close and save brass.

The best way to use the Hornady comparator and measure it that way. .0015" works for me with just about everything. If I set them all right there I'll lose primer pockets long before I have to worry about losing a case to a separation.

 

[ksubuck]

Here is what I do.

I fireform virgin cases, then neck size them and reload for their second and sometimes third use if they still chamber easily. Once they no longer chamber easily, I measure their shoulder length using a Hornady headspace gauge. I assume this measurement is very close to the true headspace of my rifle's chamber. From this measurement, I want to set my full length die so that it just pushes back the shoulder on the case approximately 0.002 inches. To do this, I remove the decapping/neck expander pin and then set the die so that it just barely misses the shell holder. I then run a case through. You can often see how far down the neck the die has resized. Keep adjusting the die further down until you see the neck almost getting completely sized. After this point, you need to slowly tighten the die down for each additional sizing. It doesn't take much. Measure the shoulder using the headspace gauge until you see the "bump." Once you have the die zeroed in, tighten the locking ring and leave it there. As long as you use the same press and same shell holder in the future, your die is now set to bump the shoulder on every case just enough to allow it to chamber with minimal headspace in your rifle.

Anyone else, feel free to chime in and call me crazy if you have a better way to do it.

 

[REDGREEN]

I invest in neck sizers for all of my toys. Problem is solved once they are set up. I also anneal all of my brass and trim to .005 under actual chamber. This has worked well for me for 50 years. Yeah, I know, us bench rest and silhouette shooters are a fickle bunch. I tired the other route, but wasn't satisfied.

 

[ElmerThud]

Here is what I do.

I fireform virgin cases, then neck size them and reload for their second and sometimes third use if they still chamber easily. Once they no longer chamber easily, I measure their shoulder length using a Hornady headspace gauge. I assume this measurement is very close to the true headspace of my rifle's chamber. From this measurement, I want to set my full length die so that it just pushes back the shoulder on the case approximately 0.002 inches. To do this, I remove the decapping/neck expander pin and then set the die so that it just barely misses the shell holder. I then run a case through. You can often see how far down the neck the die has resized. Keep adjusting the die further down until you see the neck almost getting completely sized. After this point, you need to slowly tighten the die down for each additional sizing. It doesn't take much. Measure the shoulder using the headspace gauge until you see the "bump." Once you have the die zeroed in, tighten the locking ring and leave it there. As long as you use the same press and same shell holder in the future, your die is now set to bump the shoulder on every case just enough to allow it to chamber with minimal headspace in your rifle.

Anyone else, feel free to chime in and call me crazy if you have a better way to do it.

I never neck size these days, but that's pretty much how I F/L resize, but I use a rubber 'O' ring under the lock ring for two reasons. First, it gives me the facility to pinch the die up or down to achieve absolutely exact headspace sizing. Second, the die can flex just enough to aid the case head in the shellholder to give excellent case/neck concentricity. The decap rod just needs setting up - leave it slack until the expander ball is felt in the case neck on the downstroke. As soon as it's felt, keeping the tension on the ram, tighten the expander lock nut. That should be it - exactly centralised.

Annealing brass every fourth firing does it for me.