.243 case head separation

[brubuck]

Question for the experts. Do certain calibers display casehead separation with less loadings than other calibers. I have a Weatherby Vanguard in .243 that casehead sep. shows up after about 3-4 firings. I always just bump the shoulder back. Has never come apart on opening the bolt, have caught it early.
I have started annealing, so maybe I can remedy the problem.
I have not loaded hot, according to load manuals. I know all guns & chambers are different. Anyone have ideas? Thanks Brubo

 

[Tripwire]

Re: .243 case head separation

How, exactly, are you determining this to be "case head separation"?

 

[wadebrown]

Re: .243 case head separation

How far are you bumping the shoulder back? Bumping the shoulder back too far is the fastest way to get early case head separation.

 

[Fuzzball]

Re: .243 case head separation

"I always just bump the shoulder back."

IME, no bottleneck cartridge is any more likely to stretch enough to cause a head seperation than any other. Agree with Wade, you're likely 'just bumped the shoulder back' too far; that's the primary cause of head seperations.

 

[Tripwire]

Re: .243 case head separation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wwbrown</div><div class="ubbcode-body">How far are you bumping the shoulder back? Bumping the shoulder back too far is the fastest way to get early case head separation.
</div></div>

Almost asked that question myself, first, but I'd like to know what he's seeing, exactly, before getting into a diagnosis/remedy.

Wasn't just the other day some newb on another site was very, very confused about this very topic.........

 

[brubuck]

Re: .243 case head separation

Iam sure its casehead sep. Just above the sizing mark. I have seen pics. here plenty of times. You guys have touched on I could be over bumping the shoulder, that could be the problem.
But I load for .3oowsm .270 7rem mag I have only had this problem on the .243. When I resize I turn the die down to touch the shell holder, then back it off a bit, then size the case & try to chamber in rifle. If it doesnt chamber I turn down the die a little more, try again etc. until it chambers with slight resistance. Is this the correct procedure.
Thanks Brubo

 

[milo 2.0]

Re: .243 case head separation

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: brubo</div><div class="ubbcode-body">Iam sure its casehead sep. Just above the sizing mark. I have seen pics. here plenty of times. You guys have touched on I could be over bumping the shoulder, that could be the problem.
But I load for .3oowsm .270 7rem mag I have only had this problem on the .243. When I resize I turn the die down to touch the shell holder, then back it off a bit, then size the case & try to chamber in rifle. If it doesnt chamber I turn down the die a little more, try again etc. until it chambers with slight resistance. Is this the correct procedure.
Thanks Brubo </div></div>

Sounds to me like you're setting your die right.
Have you tried the paper clip trick, to feel for seperation?
Annealing your brass will have no effect on case head seperation, unless you heat your brass too much toward the case head, then the combo might become catastrophic.

 

[The Gump]

Re: .243 case head separation

Have you gauged your chamber? It could be out of spec. I had a friend whos' .260 chamber was too long. Separated case heads after the 3rd firing.

You could get a bump gauge and bump to that length.

 

[Tripwire]

Re: .243 case head separation

Have you taken a piece of wire with a sharp 90 degree bent hook on one end and tried to see if you can feel a "catch" around the interior of the cases where what you are concerned about is located?

Have you taken a piece of the brass and cut it length wise (Dremel/cutoff wheel) to look at a cross section of the case wall to see if there actually is a thinning of the material there?

Got a camera?

Post some pics here....unless your chamber and/or sizing process is FUBAR'd all to hell, I'm having a hard time believing in "case head separation" with mild loads on 3 to 4 firings.

What brand of brass is this?

 

[brubuck]

Re: .243 case head separation

Turbo's pics in this forum are what I am seeing on my cases. I have also had flattened primers with loads a grain or 2 below book max. This has always been an issue with this gun, so I have been very careful about over charges. The gun shoots great. I think I will get a case gauge, the Hornady lock & load? I have learned alot on the internet, but SnipersHide is my go to site. Thanks again Brubo

 

[brubuck]

Re: .243 case head separation

To Tripwire it is winchester brass. Yes used the wire method.
I use a straightened large safety pin with a 1/8" bend on end.