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6.5 CM cases splitting at the base of the shoulder.

Dead Eye Dick

Command Spec 4 (formally known as Wiillk)
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May 18, 2020
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North Louisiana
Experienced handgun cases splitting the entire length and rifle cases splitting along the neck, but never at the base of shoulder where it meets the body of the case.

Now this may be a moot question because light annealing alleviates the problem. But it seems a strange place to split. This type of splitting occurs in both teh RPR and the Kimber Hunter.

Anyone have any ideas why this might be happening.
 
Sacrifice some of the cases that aren’t splitting yet and see if they’ve got a defect inside By cross-sectioning them. That is a very unusual place to split. Across two different rifles is weird too.

Agreed^^^this is an odd location for a split.

What brand of brass and how many reloadings?
 
I believe I have noted the actual location a bit wrong, for that I apologize. I have pictures of three cases below. The issue so far has been with both Hornady cases and Nosler cases. And has stated, seen in two different cases and now that we are living with our son, two different sets of loading dies and loading centers.

After decades of reloading this is an all time first for me. Seen lots of split necks, but splits starting at the bottom of the neck and into the shoulder is a very first.
0EEDCADE-4F5C-4C4E-B78B-7B89D05DAA26.jpeg
 
Sacrifice some of the cases that aren’t splitting yet and see if they’ve got a defect inside By cross-sectioning them. That is a very unusual place to split. Across two different rifles is weird too.

what’s the best (safest) cutting tool to do this with?
 
I've had several Hornady cases split like that, but that was with some really old brass. I think they had 8-9 loadings on them, and were a lot # from back in 2012 or 2013...
 
Brass is both Hornady and Nosler and the # of reloads is three or less. As stated, annealing resolves the issue.
If annealing fixes it then it’s a hardness and stress issue, you found the solution.

It’s weird. I’d want some measurements to compare from one chamber to the next.
 
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How hot is your load?@ Spife 7980 and @ 1moaoff are probly closer than my thinkin a hot load. Ive seen it split there on a few wby brass that were used to find pressure after 3 loadings/firings.
 
That is an interesting question. According to some references, it is close to max, according to other references it is close to starting loads. Go Figure.

What I have found that works, is accurate, shows no pressure signs on the primer, no excessive case head expansion or sticky extraction (Much less, blown primers or ejector ring marks on the case head) is

With the Hornady 143 grain ELD-X, uses 44 grains of Super Performance and a WLR primer.
With the Berger 144 Hybrid, uses 43.5 grains of Super Performance again with aWLR primer.

While the Berger load gives up 60FPS it gains roughly a tenth of an inch reduction in group size. The ELD-X, which I ran into quite accidentally has proven to be a very good target bullet. Groups at 100 yards, when I do my part are under a half inch. I just wish the Kimber American, which has a one inch guarantee could come even close. (For that matter, even close to its guarantee).

A final thought, the Hornady factory loads using the 143 grain ELD-X in the RPR are 2663FPS, my handloads in the RPR with the same bullet are running 2662FPS
 
How many reloads on the cases? I noticed the cases are really shiny like they have been polished with brasso or other cleaner. What are you using as a case cleaner?
 
These cases have been cleaned in a vibrator style cleaner with corn cob media. I just leave them in for a while. (Aggravates our son who we are currently staying with. Its his case cleaner).

At home, for the cases we used with IHMSA rounds, we used Nu Finish. It was always a contest to see who had the nicest rounds.
 
that is an odd split, so be clear this is happening when resizing not shooting correct?
 
Splits are occurring when shooting. I clean the cases prior to loading for several reasons, one of which is to check for faults in the cases. Also, the splits “were” occurring when using a set of RCBS dies at our son’s home ad a set of Redding dies at our home. It would seem unusual for the same issue to occur with two different sets of dies.
 
If you look closely at the top of the split. To me the splits at the top portion is indented. Like a puncture?
My guess is something is going into that case. Have no clue what and have never seen that myself. They all look very similar at the top of the split. The middle is just splitting horizontally. How’s that chamber look?
 
That’s a good point, I have not inspected the chambers. Key here is problem is occurring in both a Kimber Hunter and an RPR. Further, no issues after annealing the cases. Still a good idea to do a chamber cast. Thanks
 
That’s a good point, I have not inspected the chambers. Key here is problem is occurring in both a Kimber Hunter and an RPR. Further, no issues after annealing the cases. Still a good idea to do a chamber cast. Thanks
Apologies I missed that it’s multiple rifles. Super interesting though. please keep us informed on your discoveries.
 
Try this on.
Maybe it's not any of your gear at all.

I pick up a lot of brass at the range.
I have seen this before and have several guesses as to cause.

Are any of these cases range pickup or purchased used brass?
 
Some are and some are not. When I first purchased the RPR, not having dies to reload for it, i purchased a lot of factory ammunition. After getting initially set up, i went with Nosler brass because of reports that Hornady and Nosler may be coming from the same brass supplier. Lately, I have been picking up a lot of brass, cleaning it and now, annealing it before use. Many of the cases I have picked up were brand new, still having the “sale barn shine” on them (an old Louisiana saying about cows coming fresh from being sold at the sale barn, usually with the sticker still on thier hindquarters)

I quit using Nosler brass due to the high incident of case failures.

All said, while I pick up brass, I only use Hornady. (even Hornady brass from the least expensive suppliers runs $0.60 per round). So, if someone wants to gift me six or seven dollars, or more, I pick it up, give it a good cleaning, inspect it for flaws, anneal it and then when I have enough, put it in a case and start using it.
 
Another word on this, before annealing, i was getting a failure rate of close to 30%. Since annealing the cases failure rate comes to one or less per 50 rounds shot. Expect cases will be getting an annealing after five uses After initial annealing. (Brand new cases excepted, they will get an annealing after the second use) Will of course send them to the recycle bucket when the primer pockets expand

In the old days (that would be about 20 years ago or less) I made hundreds of 7TCU cases, .300 Whisper cases and even made some .221 Fireball cases. Winchester brass for a .223 case, from which all these were made ran about .$0.20 per case or less. When a .223 case or a TCU case split, it went to the Whisper case box to be converted. (As if I did not already make many, many Whipser cases from virgin brass.). Same with .357, .44 and 45 Colt brass. buy it in 500 packs, when a case gave it up, out it went, never a worry. And the case loss wasn’t that high.

In the very old days (somewhere along the 1970’s, money was very short and we annealed .25-06, .243 and .250 Savage cases because money was short and what we now consider very inexpensive as quite expensive when compared to our income.

So, the world turns and everything is just like it used to be.
 
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That is a high failure rate, especially after annealing (assuming that your annealing is being done correctly). I have hornady and Federal brass that I’ve worn out using medium loads (primer pockets) and have never had a failure that looks like that.

Earlier, you said “no issues after annealing”, but now you say that you are getting about 1::50 failure rate even after annealing.

This leads me to think that:
  1. You need to only use brass fired in one rifle for that same rifle. Don’t use the brass interchangeably between rifles.
  2. After firing brass through each rifle (different brass), carefully measure all of the critical dimensions for the fired brass out of each rifle. Measure at least three specimens from each chamber and record them.
  3. Review the measurements from #2 above and see if and what differences there are between them. I suspect you will see some.
  4. Compare your dimensions from #2 above to the dimensions of your brass after forming (full length sizing or neck sizing only??).
  5. Pay particular attention to:
    • OD and ID dimensions of your necks in all above cases and
    • Headspace dimensions, especially with respect to each other
  6. This issue is a process related issue with relation to your rifle chamber dimensions.
 
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Some good ideas, some of which have been already implemented. Others I will defiantly do.
 
I suspect the brass that is failing was damaged before you got to it.

Scratches from overgassed cheap barrels that have burs on them.

The imperfections are small and easy to overlook.

I run my range brass till it shines like a diamond and is easier for me to spot problems .

Firmly believe nothing you have caused.

The softer annealed brass will not split as fast, possibly smooth over the tiny glitch? That is a wag.
 
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