Op stated one round had wrinkles I can only "assume" he didn't tap his loaded rounds and got an overhead view of his loaded rounds to check that all the powder levels were uniform in the cases. I did that once on a 270 Weatherby. I also pushed the neck down in resizing from to much lube and not brushing the necks sufficiently. I also now periodically take apart the sizing die and clean the ball and die chamber and vent hole.
Novice reloader looking for help
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Jeff Heeg osoh
Well-Known Member
Surprisingly the majority here are more concerned with if and how much case lube was used, and didn't see that the brass had issues during being fired and not during sizing.
The worst is most ignored the real dangerous issue of the case head separating. Picture zoomed up from original post.
osoh
The worst is most ignored the real dangerous issue of the case head separating. Picture zoomed up from original post.
osoh
vancewalker007
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That's a case head separation. I've seen it many times with my 7mm STW back in the old days when we made cases out of 300 Weatherby brass. You had a leak in that case that caused a pressure differtial where the pressure pushed forward towards the neck and made those dimples. You are likely over bumping the shoulder causing brass thinning just above the belt. Drop your shoulder bump to 1-3 thou and be really careful shooting any of that brass you've been over working. Check for bumps using a paper clip or dental pick. Toss the ones that have signs of the start of separation.
UncleDano
Well-Known Member
This whole thread has turned in to a dumpster fire. Just goes to show you how confusing and misleading it can be if you don't present all the facts and info needed in the first statement posted. Good luck getting anything helpful out of this mess!Hold on, you are not sizing any of theses cases? Guess that makes sense as you did not lube them at all. So what was your process. Started with new cases, Did you neck size? Chamfer? Primed the case, charged the case then seated the bullet. You fired the cases. Any cases deform on the first firing?? Second firing, you did not FL size or bump, followed same process as above, clean, neck size and prep, prime, charge and seat? Did the rounds chamber easily? If the cases had been fired in a SAMMI chamber it should expand enough to feel tight when rechambering and closing the bolt. If not the cases are most likely Not sealing the neck and shoulder area. The gas blows back along the Case wall collapsing it in. You will also see powder residue on the neck shoulder area of the fired case when this happens sometimes. It may be the brass you bought and the chamber you have are on the opposite ends of SAMMI spec? The fact it happens occasionally suggest this as it only takes .001 too much outside of the range where it will seal to cause this issue. We see it when our cases need annealing from being resized. The brass hardens and will not expand enough to seal the chamber and send all the gas down the barrel. We anneal every firing now. Your situation is not due to over working or hard cases as it is new brass, unless it was not annealed by the manufacturer. Low pressure could be the cause but I think you had enough pop to expand the case. We fireform BRA and SS cases with 10% reduced loads and they blow out into the chamber. Your mild load should expand the brass into the chamber. I think it is the fit of the case into the chamber not the reduced charge. Also check all the case heads. When brass is allowed to stretch and does not seal it could begin to separate. If you have a 7mm chamber go gauge check your chamber size and head space or maybe fire some factory ammo or if you have did it function fine?
UncleDano
Well-Known Member
Wet
All I can say concerning this issue is as I stated. This happened to me once when I first started loading the case looked like the one in the pic. The gunsmith at the time at Alpine shooting told me to readjust my die and to be conscious of powder in each case. I was using an RCBS load dispenser and I didn't check each case. It could have been that it didn't drop a full measured load? Or over dispensed? It has not happened again. I was new to reloading and got in a hurry. Thinking that all loads from the dispenser would be the same. That was in around 1990. I'm still learning from all the diverse group on this site.
jonkershner
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![20220313_193040[6887].jpg](https://r2d2.www.longrangehunting.com/attachments/340/340739-ff68677c8200a5cc93afc361fb0ec3c6.jpg)
Carlos 88 nailed it on page1.
Jeff Heeg gives a nice close up and Vance Walker explains it well.
It is purely and simply a case head separation which is very very common on belted magnums like 7mm mag, .300 WM, etc
When the head spacing is not right, either due to something wrong w how its set on the rifle, or the cases after 2 or 3 firings are not trimmed correctly and/or are not bumped back .002, then this is VERY commonly the result.
A belted magnum is supposed to headspace off the belt on the case head, but when it is fired and elongates and stretches, then is not trimmed or bumped back correctly, the next firing, it is not headspaced on the belt correctly and the belt may get slammed into place stretching the case right above the belt.
Then if you over size it, you further
fatique the metal above the belt by compressing it back onto the belt.
Then you fire it again and it is stretched and fatiqued at that same spot again. 2 or 3 firings you get either total case head separation just above the belt where the case head is severed completely or you get a leak there of high pressure gas.
When you get high pressure gas on the outside of the cartridge and the pressure outside the cartridge is more than that inside the cartridge as the bullet leaves, it pooches the brass in at the neck area as you showed in the photo.
This is a partial case head separation/leaky crack just above the belt where the metal fatique is focused.
If you either use a paper clip w hooked end you will feel the crevice inside the brass, or if you take a look or a photo w a bore scope you will see it clearly.
All of the posters above got this right.
Pressure differential from the leak above the belt where case head severing is imminent exerted on the outside of the cartridge pooched it in.
I have seen this before.
Its very common on belted magnums.
The solution is correct trim, correct amount of full length sizing, and using comparators to get the shoulder bump just right about .002
so the cartridge headspaces and seats off the belt snugly every firing
Jeff Heeg gives a nice close up and Vance Walker explains it well.
It is purely and simply a case head separation which is very very common on belted magnums like 7mm mag, .300 WM, etc
When the head spacing is not right, either due to something wrong w how its set on the rifle, or the cases after 2 or 3 firings are not trimmed correctly and/or are not bumped back .002, then this is VERY commonly the result.
A belted magnum is supposed to headspace off the belt on the case head, but when it is fired and elongates and stretches, then is not trimmed or bumped back correctly, the next firing, it is not headspaced on the belt correctly and the belt may get slammed into place stretching the case right above the belt.
Then if you over size it, you further
fatique the metal above the belt by compressing it back onto the belt.
Then you fire it again and it is stretched and fatiqued at that same spot again. 2 or 3 firings you get either total case head separation just above the belt where the case head is severed completely or you get a leak there of high pressure gas.
When you get high pressure gas on the outside of the cartridge and the pressure outside the cartridge is more than that inside the cartridge as the bullet leaves, it pooches the brass in at the neck area as you showed in the photo.
This is a partial case head separation/leaky crack just above the belt where the metal fatique is focused.
If you either use a paper clip w hooked end you will feel the crevice inside the brass, or if you take a look or a photo w a bore scope you will see it clearly.
All of the posters above got this right.
Pressure differential from the leak above the belt where case head severing is imminent exerted on the outside of the cartridge pooched it in.
I have seen this before.
Its very common on belted magnums.
The solution is correct trim, correct amount of full length sizing, and using comparators to get the shoulder bump just right about .002
so the cartridge headspaces and seats off the belt snugly every firing
You are sizing your brass too much. You have a case head separation that leaked gas into the chamber. Get a hornady headspace comparator tool. Going by feel is pretty vague if you are not stripping your bolt. The comparator is easy to use.
vancewalker007
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We used to see that happen on our STWs years ago as we were making cases out of 300 Weatherby cases. They'd get over worked pretty fast and pop, they'd get a leak or separate completely. The cases would suck in like that because of the vacuum caused by the back of the case leaking pressure which drops pressure between the hole in the case and bullet going down the barrel. You get to find out where the pressure relief holes are on your action, not that fun.
Lee Goodwin
Well-Known Member
If the wrinkles occured after you fired the round it may be your shoulder is set back too far. Just a guess. Pics please.
OldSchoolHunter
Member
The only time I saw something like that was a lube dent during resizing.
This thread is a perfect example of the knowledge that can be shared and passed on to others. This is a case head separation and the picture clearly shows it. Thanks guys for passing along the correct diagnoses, it is up to the end user as to what they do with it. IMO the previously fired brass is probably on a collision course with the same end result and should be carefully examined or taken out of service. Get some new brass and learn how to set shoulder bump correctly. Peterson Long Brass is a viable option and is available periodically as well as other name brands.
