Cracked Cases

[wrangler]

it's called case head seperation. each time you size a case the brass is streched. if a case has been reloaded too many times that's what you end up with. if you have a fairly tight chamber there really is no need to full length size every time. a neck sizer won't put the unneeded stress on the brass. it's not related to pressure. time for some new brass!

[dbllunger]

Skipped all the way to the front.  Problem is real simple....TOO MUCH HEAD SPACE....!!!! Not a major problem if your rifle is accurate.  I have a 300wm that drives tacks but eats brass.  Not uncommon on belted mags because they seat on the base instead of the neck.  If if drives tacks live with it and count reloads, but if not have it set back to minimum and it will shoot a couple more times.  Better yet go to to a mag based on the 404 and the brass will last as long as the old 06.  Not a crisis as it never does it the first round,  and if it it does then you have major problems and a 1-2 threads will be needed.  Personally screw the belteds with the new mags factory loaded with factory brass.!!!!!!!!!!!!!!!!!!!!!  Load them to the top and and then some and they like it...just like the old college co-ed.   Man those were the days.

[CP]

Thanks for all the replies.  The rifle in question is a sporterized Remington made model 1903A3 30-06, manufactured in Jan 1944.

Headspace checks good.  Maybe it’s just weak brass but since she’s going on 65 years now I’m going to back off the load. 

[jeff100]

Is your load hotter than max load in the manuals for the powder you're using?

Have you chronographed the load?

Can you provide a photo of the end of the case, so we can get a good look at the primer (for primer analysis)?

[CP]

Is your load hotter than max load in the manuals for the powder you're using?

No

Have you chronographed the load?
No


Can you provide a photo of the end of the case, so we can get a good look at the primer (for primer analysis)?

I'll try, but I’m not too good at photography

[CP]

These look nasty when enlarged like this:

[deaddog]

Skipped all the way to the front.  Problem is real simple....TOO MUCH HEAD SPACE....!!!! Not a major problem if your rifle is accurate.  I have a 300wm that drives tacks but eats brass.  Not uncommon on belted mags because they seat on the base instead of the neck.  If if drives tacks live with it and count reloads, but if not have it set back to minimum and it will shoot a couple more times.  Better yet go to to a mag based on the 404 and the brass will last as long as the old 06.  Not a crisis as it never does it the first round,  and if it it does then you have major problems and a 1-2 threads will be needed.  Personally screw the belteds with the new mags factory loaded with factory brass.!!!!!!!!!!!!!!!!!!!!!  Load them to the top and and then some and they like it...just like the old college co-ed.   Man those were the days.

+ 1 I think you got it right.

[jeff100]

Primer pic is fine, and looking at these primers I would agree with you, I see no signs of excess pressure in the primer analysis.  I use a chronograph for all my testing these days, but I spent a couple of decades without one, and got pretty fond of primer analysis for evaluating rifle loads.  Even with the chrono, I still do constant primer analysis as an extra data point and reality check.  Old habits die hard I guess. 

I'm agree with everyone else who has suggested case head separation is most likely from too much head space...thanks for posting the picture...

Jeff