What causes this? 7mmsaum. Full length resized. Warm but not hot load. 2nd and 3rd firing. Good Adg brass.
Attachment 131407
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What causes this? 7mmsaum. Full length resized. Warm but not hot load. 2nd and 3rd firing. Good Adg brass.
Attachment 131407
Hell that's one thing I've never seen I be interested in here what others think it is.Quote:
Originally Posted by Tahr
Sorry I'm if no help.
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Maybe your annealing technique could have something to do with it?
I've seen it on a 223 where too many reloads and no annealing.
I did anneal after one load. Maybe too hot?Quote:
Originally Posted by Mathias
Brass is too hard/brittle
It’s certainly the hardest/ toughest brass to FL resize with a manual press handle
So I stuffed it annealing then?Quote:
Originally Posted by 7mmsaum
can you show an unfired load from the same batch
What do the bases look like?
Just a question to get an overall picture.
Also how many did you fire and have any others given you any sign or were these the first two in that batch that you reloaded.
Again just for my own reference in what to look for, ie warning signs. Thanks.
Quote:
Originally Posted by Tahr
Yes
Most likely after annealing the cool down period was too quick
ADG brass is well annealed before purchase so I would be tempted to load it 4 times minimum before re annealing
As in dunking them in water..? That's what I do!Quote:
Originally Posted by 7mmsaum
Thank you for this.Quote:
Originally Posted by 7mmsaum
Bruce
Bases are good. No scribes or marks. I "think" it started after I annealed. Powder is Hybrid100V and R26. 162 grn at 3k out of 22" barrel so its up there. Have fired maybe 100 shots through the rifle and none of the brass is older than 4 firings.Quote:
Originally Posted by Sideshow
I will start again with new brass, not anneal, and track what happens.
Attachment 131413Quote:
Originally Posted by gonetropo
That’s not annealing, an instant cool is Tempering which will make the brass harder/brittleQuote:
Originally Posted by outlander
i would say it got hot-cold too quick and went brittle, annealing normally shows of a blue-red rainbow (sorry you lgb a...z lot) than as a uniform colour of almost black.Quote:
Originally Posted by Tahr
Unlike steel, brass does not harden with rapid cooling, it makes no difference if it is dropped in water or left to air cool. The only way to harden brass is by working it as in sizing it.
A few questions.
How do you anneal them?
Do you clean your brass and if so how and what additives do you use?
Never seen that happen after a only a couple firings.
One thing I notice is that the carbon on the case appears to continue past the cartridge neck and onto the shoulder. To me this would indicate that the case is getting sized too much, pushing the cartridge headspace back too far; allowing gas past the neck and onto the shoulder. (or the headspace on the rifle is too long).
If you have headspace comparators then try measuring a sized case vs a fired case. Id bet the headspace on the sized case is too shot. (meaning you should back your full length die out - or try neck sizing only)
@Tahr if you know someone with an AMP machine, it could be possible to revive this brass with an accurate anneal. I have no proof with that this would work, but it makes logical sense.
I have had that sort of cracking of the neck in .257 AI cases. It occurs when I do not anneal at all. Usually get a split down the neck and neck base.
As stated above quenching in water does not impact annealing.
My guess is not annealling far enough down the shoulder.
Dunno if it is temepering/hardening but I never rapidly cool my brass.Quote:
Originally Posted by 7mmsaum
Odd to do that after a couple firing so my guess is over annealing and a host of other possible issues.
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Thank the stars that you're wrong. Almost had me pulling bullets there.Quote:
Originally Posted by 7mmsaum
@Tahr do you anneal below the shoulder?
No. I pretty much just do the neck and some shoulder.Quote:
Originally Posted by outdoorlad
I "anneal" using my gas stove (single burner camping thing) and heat the neck holding the base of the case and twirling it. When I feel the heat in my fingers I dunk the case in water.
My guess is under rather than over annealing
@Tahr I would suggest that your cases aren't being annealed enough. Unless you have hands of steel there is no way that you can get the necks hot enough and still hold onto the case base. At one point I touched the base of a 6.5-284 case straight out of my AMP annealer and it instantly burnt my finger tip.
If it is under annealed, it is pretty shit brass to do work harden within a couple firings to cause that seperation.
It has to be a combination of things.
Even before the annealing craze took on you could get 5 or 6 loads out of a warm load case with most brands of brass and I don't recall seening the neck separate like those above.
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Not far enough annealing past shoulder, about 5mm needed otherwise you had a hard brass to soft brass junction at neck and shoulder junction which is most likely the highest stretching/stress region on the cartridge when fired and causing case not expand uniformly in this region.
black stuff - just carbon as stated earlier, can darken more with gas annealing
Rapid cooling of brass is safe as houses and does not harden it.
One can tell if you over annealed brass with gas, first you can see the flame slightly change colour as the surface zinc in the brass burns out of the copper, also the more than usual shinny tin look to brass once annealed - not the usual annealed colour. Anyway I have fired over annealed brass as fouler shots before range shooting and never had a case separate nor any other problems apart from maybe a dented shoulder when seating projectile (but they still fire form out and case reharden with use)
Have these cases been heck turned?
I've been getting split necks upon 1st firing of my norma brass, maybe 1 in 3. 300 saum necked down. 62grains of 2213sc with a 140vld . Real mild, accurate load. I wouldnt have thought they would need annealing or anything from new? Any reason why this would be happening?
NoQuote:
Originally Posted by zimmer
Do you really need to anneal the cases, have reloaded for 40 plus years and never annealed any of my brass. I do get split necks after a while but usually get quite a few loads from them before this happens. Some brass is better than others and seems to go forever. Most of the time the first thing to go is the primer pocket enlarges and then I chuck the brass.
I suppose different rifles have different effects on brass too so there are a lot of variables out there.
thar has invented a new sabot wildcat :thumbsup: @Mooseman i find federal brass the worst ive tried as far as enlarged primer pockets go
I have a SAUM 180gr running at 3050 fps with up to 12 firings per Norma brass.....no issues yet.
There appear to be heavy vertical scratching on all the necks, and my guess that is replicated inside too...could be huge stress at the point of separation if those necks are as tight as they look. Do not pull your expander up through the re-sized neck......remove it from the stem, punch out the primer, clean the inside with a brush, lube the inside of the neck with something like sizing lube, then install the expander and press down from the top. Even better get a K&M expander to do the job.
The other notable marks are at the top of the neck...quite shiny while the rest of the neck is overly black from gas leakage. Properly sized and annealed necks should have very little powder residue, and in fact if all the planets have aligned you should get witness marks on the neck from the powder representing the number of bolt lugs....! Have you checked the overall chamber length to the top of the neck and the headspace of your loaded round compared to a newly fire-formed case...best to have half to one thou clearance at the shoulders, and 10-20 thou at the top of the neck. That is not critical as long as all the brass is trimmed to the same length.. Also ensure there is no carbon ring formed at that critical junction of the neck and freebore.......?
Regarding annealing....it is difficult to over anneal except if the heat migrates to the base, then you are in trouble.It is not detrimental to cool copper and its alloys so get that heat down past the shoulder base....heat the neck and shoulders very quickly, and dunk it to prevent the heat migration. Lapua brass has very clear and consistent annealing evidence.....replicate that and you are on the right track.
That was an interesting read @Longranger
In your opinion how important is it to anneal brass? And when?
I’m guessing it’s to do with your annealing technique of not doing to just below the Shoulder & with a healthy load? There’s a guy on trade me in Wellie who offers annealing, our club Has bought an AMP annealing machine which is magic, I’d be happy to run your brass thru it if you like.Quote:
Originally Posted by Tahr
Seen the same thing happen with a friends 300WSM. The headspace was too great i.e. over sized as mentioned by ChrisW and the three times fired cases were loaded with a new different batch of powder which was at least 1.5 grains hotter than the previous lot.
It is only important if you want accurate loaded brass. Annealing is essential if you FLS and want consistent headspace and neck perfection in both runout and interference fit on the projectile. I do anneal after every firing, but with a proper annealer. Otherwise just carry on and dispose of the brass when the neck splits, then get new annealed brass......by the way the first question needs addressing...why do the manufacturers anneal brass if they consider it an unnecessary step.....?Quote:
Originally Posted by Danny
tahr....what you might try is annealing with a timer, a flame mounted on a movable stop, and a drill in a jig......spin the brass in the drill at the same place on the flame (preferably the body/shoulder junction and the heat will migrate to the neck) and after the necessary time remove the flame, undo the chuck and drop the case into water.....develop a system so the time, flame placement and drill speed are all consistent, and you will be good to go. I am presuming you know how to correctly headspace your brass after sizing......?
Thanks for the reply to my post @Tahr
Shot with 7mm SAUM with mirage and wind conditions at 400yds....not perfect but getting close. These rounds are annealed everytime, headspace and neck interference closely controlled, and all the usual brass prep attended to each loading.
One difference is the chamber is tight and close attention is needed to brass migration affecting the neck wall thickness....reaming and turning needed sometimes to maintain consistency, and voila.....!
