How often do you anneal your brass

Polishing the inside of the neck

Pete Wass said:
Another area is the inside of necks. Not only does carbon build there but a patina does as well and even with the carbon removed, the patina will make seating un-smooth. Polishing the inside is the best situation but just removing the patina will make seating a lot more consistent.Pete
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Pete, what do you feel is the best way to polish the necks. I usually use an old brass bore brush, but I'm open to suggestions.

Roy
 
Annealing tool

Has anyone used the gadget which attaches to a propane bottle? I have one I got from the Woodchuck Den. It has a loop on the end with about 10/12 holes punched in it. It seems to work well, but I don't really know.

Roy
 
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This is a tough one Rouah

Roy Allain said:
Pete, what do you feel is the best way to polish the necks. I usually use an old brass bore brush, but I'm open to suggestions.

Roy
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One of my shooting friends has come up with a system where he uses Never Dull on a dowel in a drill or a some power source. I have used steel wool wrapped around an old bronze brush. It doesn't stay put very well though and doesn't last very long. Just brushing will not keep necks clean enough. the carbon and patina will still be there. This friend and I purchased that Stainless Steel media and it works very well. By the second cleaning, all the carbon is gone inside the cases. He does it for me. He has developed a system that works the very best.
 
They work

Roy Allain said:
Has anyone used the gadget which attaches to a propane bottle? I have one I got from the Woodchuck Den. It has a loop on the end with about 10/12 holes punched in it. It seems to work well, but I don't really know.

Roy
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but are not easy to use. The best thing I have seen to date is the induction tool garage mechanics use to loosen rusty bolts and nuts. The tool is $400 ish or so but there is no flames and once the process is figured out, the cases look like they are directly out of the box when new. There is a You tube on this. I think he heated them for 6.5 seconds. No quenching or anything. A very clean and simple process. I have looked a time or two to find a simpler, less expensive unit. There are heaters for wax carvers but I don't think they would get hot enough for annealing case necks.
 
I don't anneal. Never really had a need, or I'm too dumb to realize I did. But since the topic comes up a lot, I wrote up a bit on how annealing works - not how to do it, but what it is and what you're doing when you heat up that brass. I won't repeat it, since you can read it here:The Science of Cartridge Brass Annealing
 
Damon,
That is a nice article that you put together. But it contains a misconception, which is that brass keeps getting harder the more it is worked. If this were true, then brass would eventually be stronger than steel after lots of work hardening, which we know does not occur. Actually, work hardened brass approaches a yield stress of about 33 ksi (compared to 10 ksi for soft brass) and goes no higher. Thus for the shooter, there are two ways to get consistent brass. One is to anneal after every shot, which returns yield stress to 10ksi, so long as the annealing process is perfectly consistent. This is an important caveat, though, since we know that it is difficult to make anything perfectly consistent, particularly something involving flames and heating times of a few seconds. (Heating for 5.5 seconds versus 5.0 seconds is a 10% difference.) The other way to get consistent brass is to never anneal. After lots of firings, every neck has a yield strength of 33 ksi. With this method, you don't have to worry about the consistency of your process, because there is none. Just based on feel of bullet seating force, I estimate that a 30BR with 0.330" chamber and 0.002" clearance reaches this asymptote in 15-20 firings.

Keith
 
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mks said:
Damon,
...........The other way to get consistent brass is to never anneal. After lots of firings, every neck has a yield strength of 33 ski. With this method, you don't have to worry about the consistency of your process, because there is none. .......

Keith
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It doesn't work that way in the real world at my reloading bench with both my 223 and 308 cases. (which I currently do the most shooting with.) To get the bullet to seat smoothly and uniformly, the case neck diameter must be left large enough so that the bullets will often grip way too loose. So then I resize the neck down to a snug diameter and experience the other extreme in which the bullet encounters much initial resistance and suddenly pops or jumps down into the neck. Any kind of felt resistance during the seating that causes the bullet to seat harshly into the case like that has always resulted in greatly reduced bench accuracy for me.

At one point I thought part of the problem was due to my blunt flat-base bullets. My switching to the boat tail bullets with a more gradual slope at the bullet base still seated just as badly.
 
Keith - that is counter to the data I've seen. The ASM and ASTM specs for C26000 cartridge brass show that annealed brass is closer to 45ksi in ultimate strength, while work hardened samples can get as high as 95ksi, and that both yield and ultimate strength increase with work hardening. Am I missing something? I purposefully left some of the numbers out because not all brass is made from the same alloy, and used C26000 data because I had it. Of course, eventually the work hardening stops (She can't take no more cap'n!) - but the brass is quite brittle at that point, and it's in that state that you see split necks.
 
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Anyone else notice this while doing case prep on brass that has several firings?
Some feel different in my Harrel bump die. less sizing seems to be what i am feeling. I mark those pieces. When at the neck chamfering stage those same pieces feel harder when cutting the chamfer than the others. When in the bullet seating process using an arbor press and wilson dies, those same pieces seat the bullet with a noticeably less amount of force.
All the above prompted me to anneal for the first time. All of the annealed brass went throughout each step without any noticeable difference. This seemed to help with the occasional flyer.

If any of this sounds familiar to you. It wouldn't hurt to give annealing a go

Tim
 
I don't like to waist the brass so i anneal every time. I still shoot them well over 30 times, maybe close to 50 by now. At long range, if you don't it's easy to see. Bullet release has to be the same if you want to shoot small and be consistent...... jim
 
Damon said:
Keith - that is counter to the data I've seen. The ASM and ASTM specs for C26000 cartridge brass show that annealed brass is closer to 45ksi in ultimate strength, while work hardened samples can get as high as 95ksi, and that both yield and ultimate strength increase with work hardening. Am I missing something? I purposefully left some of the numbers out because not all brass is made from the same alloy, and used C26000 data because I had it. Of course, eventually the work hardening stops (She can't take no more cap'n!) - but the brass is quite brittle at that point, and it's in that state that you see split necks.
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Damon,
Oops, I have my numbers wrong. Olin cartridge brass alloy 260 yield stress varies from 10 ksi to 33 ksi annealed and from 21 ksi to 93 ksi roll tempered (work hardened). Tensile strength varies from 45 - 61 ksi annealed and 49 - 104 ksi rolled.

The same concept still applies, though. If you run the calculations, what you find is that the deformation becomes more elastic and less plastic with each sizing and firing. For BR spec chambers, strains are less than 1%, which even for the most work-hardened case means that the material never reaches the tensile stress at which failure occurs. For instance for a 30 BR with 0.002" clearance, the strain is 0.65%. Failure thus eventually occurs due to cyclic fatigue, which may take thousands of cycles. Or a defect in the material.

It takes at least about 0.004" clearance for the brass to reach tensile stress (split necks) for the most work-hardened state. But this large a clearance is, in general, not BR quality.

Cheers,
Keith
 
mks said:
Damon,
Oops, I have my numbers wrong. Olin cartridge brass alloy 260 yield stress varies from 10 ksi to 33 ksi annealed and from 21 ksi to 93 ksi roll tempered (work hardened). Tensile strength varies from 45 - 61 ksi annealed and 49 - 104 ksi rolled.

The same concept still applies, though. If you run the calculations, what you find is that the deformation becomes more elastic and less plastic with each sizing and firing. For BR spec chambers, strains are less than 1%, which even for the most work-hardened case means that the material never reaches the tensile stress at which failure occurs. For instance for a 30 BR with 0.002" clearance, the strain is 0.65%. Failure thus eventually occurs due to cyclic fatigue, which may take thousands of cycles. Or a defect in the material.

It takes at least about 0.004" clearance for the brass to reach tensile stress (split necks) for the most work-hardened state. But this large a clearance is, in general, not BR quality.

Cheers,
Keith
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No disagreement there. I may go revise my article to make it more clear - what you write here is exactly what I meant to convey. I was also thinking about writing up a quick study on neck clearances and neck stress/strain. Sounds like you've run the numbers already. I'm still on the fence as to whether or not I think annealing matters for BR. I think it can help keep your cases together for sloppier chambers (i.e. non-BR), but I don't shoot enough benchrest to have a strong opinion based on experience, as I mostly shoot High Power, and even then I try to run clearances on the tighter side.
 
I think you would be better to use a strain gage and see what it takes to seat a bullet. same case 10 times with out annealing and do the same thing annealed. You will get a better idea why you anneal Every time you size the numbers go up, without annealing........ jim
 
jim1K said:
I think you would be better to use a strain gage and see what it takes to seat a bullet. same case 10 times with out annealing and do the same thing annealed. You will get a better idea why you anneal Every time you size the numbers go up, without annealing........ jim
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Jim,
Not necessarily. If you are using low neck tension, the seating force decreases as you size more times without annealing. In fact, it can decrease so much that the bullet just drops into the case.

Keith
 
I don't mean the force with different size bushings but use the same and size and seat a bullet. when i do ten compare the the difference in seating pressure and do each one not annealed and annealed. If you are annealing right you will find the seating pressure is more uniform and the non annealed will gain seating pressure with each sizing and seating. You must fire it and size each time with both sets. I anneal every time and cases with 30+ loadings take the same amount of pressure as they did new. I use to do it every 3rd loading and i watched the seating pressure rise on the second and the 3rd loading. At long range i can tell by the amount of vertical in the group, i try to hold 2 lb. in seating pressure, i'm using .002 neck tension and that gives me like 26-28 pounds of seating force for the most. Now if you resize and load again it will increase on some case to over 30-35 range, and the next firing some even get more. Like i said at long range it is really easy to see...... jim
 
jim1K said:
I don't mean the force with different size bushings but use the same and size and seat a bullet. when i do ten compare the the difference in seating pressure and do each one not annealed and annealed. If you are annealing right you will find the seating pressure is more uniform and the non annealed will gain seating pressure with each sizing and seating. You must fire it and size each time with both sets. I anneal every time and cases with 30+ loadings take the same amount of pressure as they did new. I use to do it every 3rd loading and i watched the seating pressure rise on the second and the 3rd loading. At long range i can tell by the amount of vertical in the group, i try to hold 2 lb. in seating pressure, i'm using .002 neck tension and that gives me like 26-28 pounds of seating force for the most. Now if you resize and load again it will increase on some case to over 30-35 range, and the next firing some even get more. Like i said at long range it is really easy to see...... jim
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Jim, What are you using to measure the amount of pressure required to seat a bullet ?

Dick
 
jim1K said:
I don't mean the force with different size bushings but use the same and size and seat a bullet. when i do ten compare the the difference in seating pressure and do each one not annealed and annealed. If you are annealing right you will find the seating pressure is more uniform and the non annealed will gain seating pressure with each sizing and seating. You must fire it and size each time with both sets. I anneal every time and cases with 30+ loadings take the same amount of pressure as they did new. I use to do it every 3rd loading and i watched the seating pressure rise on the second and the 3rd loading. At long range i can tell by the amount of vertical in the group, i try to hold 2 lb. in seating pressure, i'm using .002 neck tension and that gives me like 26-28 pounds of seating force for the most. Now if you resize and load again it will increase on some case to over 30-35 range, and the next firing some even get more. Like i said at long range it is really easy to see...... jim
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Jim,
Yes, that is what I thought you meant. With the first several sizings, seating force increases. But when you get to a certain point in work-hardening, the neck recovers elastically after sizing so much that seating force decreases relative to the first sizing. 0.002 neck tension is probably low enough to see this, so my guess is that you are annealing before you get to the reduced seating force phase.

If annealing works for you, great. All I am saying is that there are two ways to get to consistent neck tension. I don't know which is best, because I haven't quantitatively compared them.

Cheers,
Keith
 
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Keith -- It's been my experience that whether bullet pull is greater or less with more firings depend on the kind of die used. If you use a bushing die only, you get less tension after about 4-5 firings. If you use a die with an expander, it gets greater.

Of course, it is the spring back of the brass at play, so which way things go depends on whether the last operation was a "constriction" or an "expansion."

As far a long range consistency goes, I always "oversized" .001 or so -- however much it took so that the last operation was with a specially sized, polished mandrel, to take the the i.d of the neck UP to desired size. Didn't have to anneal, and the final bullet pull was extremely even. Nor was I moving the brass all that much.
 
My two cents, I've been playing with Annealing by doing it every time and have found that at a point my tight groups seem to open up because I us a tight neck to start with, so I'm going to try annealing once and see how many times I go before I start to feel the difference in neck tension or the groups get bigger. I think there maybe a happy medium that when the brass starts to work harden after so many firings its time to anneal again, hope this make sense because mine seem to work best after about the third firing!


Joe Salt
 
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