by Ken Howell
The subject of annealing cases keeps coming up again and again in the Campfire forums, as if it had never been discussed there before. I for one have gotten awfully tired of answering the same questions over and over, so here’s the section on annealing from my out-of-print book, Designing and Forming Custom Cartridges. In years to come, this article in Smokelore will be easier to find, looking back, than old threads in the Campfire forums.
OMITTING or deciding against annealing can be a costly shortcut. You may never have to anneal a case, but if you do, it’s easy. A cartridge designer once gave me a short, necked case he’d formed from a longer rifle case. He had not annealed it before he necked it down. The new neck was the upper part of what had been the body of the original cartridge. He had trimmed away the original neck and at least part of the shoulder. He may have loaded and fired it but not more than once; he may have resized it once more. But before he got around to loading it again, the entire neck split in several places and peeled back in curled strips.
I’ve since used the body of that case as a ferrule for a file handle. I wish I’d saved it to show you what omitting a necessary annealing can cost in terms of case life. He’d put a lot of work into shortening, necking, and reaming expensive cases. In neglecting to anneal them, he’d shortened their useful life to just one loading.
Unfortunately, many who modify cartridge cases both fear and ignore annealing, and others either hurry it too much or overdo it. Short case life, sometimes even canceled case life is the result of both misunderstandings of how important annealing can be and how to anneal the appropriate portions of cases properly. Annealing leaves the neck, the bullet-gripping portion of the case, soft enough to be cold-worked several times — by firing, then by resizing, again and again — but another annealing may become necessary later. Knowing when it’s necessary to anneal and how to do it — especially how not to overdo it — marks the expert former of custom cases. It’s not so hard to understand, and it’s dog-simple to do right, so there’s no good reason to do it wrong or to omit doing it at all.
Case necks sometimes need to be annealed again, to extend their useful life after a long succession of firings and resizings have work-hardened them. When case necks start to split, the rest of that batch of cases may need to be annealed again.
Case necks, shoulders, and sometimes their upper bodies often have to be annealed before the case gets drastically modified. One drastic case modification that requires annealing is familiar to most wildcatters — necking the case up or down by more than one caliber step or by more than one die will re-form it — necking the .30-06 down to smaller than .270 or .280 or up to larger than 8mm, for example.
Another drastic modification is re-forming the case body to substantially smaller or larger diameters — swaging a case with a nearly cylindrical body, a shoulder, and a neck down to a long taper, for one example — or blowing a tapered case out to nearly cylindrical.
Remember, cases come annealed enough to accommodate the moderate up-down working of several repeated firings and resizings. Below the neck, on the shoulder and upper body, the softness from annealing fades gradually to the hardness range of the lower body and base.
The farther down the case it’s necessary to reshape it — up or down, larger or smaller — the more it needs further annealing. Shortening a case so drastically that part of the shoulder or the upper body becomes the new case neck always requires annealing to make the originally harder shoulder or upper body soft enough to be a good case neck. If this shortening of the case also includes necking the old shoulder or upper body radically up or down, annealing that portion of the case becomes even more critical to long case life and good performance.
Extra working of the neck — from either the small but repeated reworking in a lot of firing and shooting or the single drastic renecking to a larger or smaller caliber — hardens the brass and shortens the working life of the case. Annealing gives a tired case a new start, if you don’t wait too long to do it.
Neck annealing is often advisable if not necessary whenever you form a case neck to another caliber, as handloaders of most wildcat cartridges know. But we often form cases for one factory cartridge into the shape of another factory cartridge to make a custom case. This re-forming cold-works the brass, making it harder and more brittle. Annealing softens the neck, to offset the cold-working and to retain the resilience of softer brass. If the neck is to stay the same, but the body is to be blown out, annealing usually isn’t necessary unless the expansion of the body is radical.
The body, once you’ve expanded it, doesn’t have to be expanded again. But the neck gets worked up and down with every firing and resizing. The expanded body isn’t stretched tight over anything, either. But the neck of a loaded case is stretched tight over a bullet. It’s under a stress that doesn’t affect the hardness of the brass in the shoulder or the body.
You can re-form new brass that’s never been sized or loaded, without having to anneal it (the factory annealing is enough), if
Brass that’s been loaded and fired again and again, has sat around for years, or has been passed along from one handloader to another probably ought to be annealed before it’s re-formed for use as a different cartridge.
Proper annealing seems so ticklish, some handloading experts flatly advise against it — but they’re usually not wildcatters, so they get along with factory brass and see annealing only as a means of restoring resiliency to the necks of tired cases. Also, too much of what has long been printed about annealing has sired and reared a family of false ideas that have led handloaders to ruin a lot of good brass by too much or too little annealing. Buying new ready-formed brass isn’t always a practical option, even for some well known factory cartridges. It’s almost never an option for the fellow who wants to load wildcat or obsolete cartridges.
So, despite some otherwise worthy advice, the need for annealing can be inevitable if the brass is to be fit for handloading. And for storage — brass inadequately annealed can split sitting in the box, if it sits around for a while before you call it up to active duty. But overannealed brass is just as thoroughly ruined — this probability is what lies behind the experts’ concern about amateurs’ annealing their cases.
Overannealing is a double danger. Only the neck, shoulder, and upper body can be safely annealed at all. The rest of the case must retain its original hardness. The head in particular has to be hard — which is why the manufacture of good brass requires enough draws to work-harden the head. The head (especially) can’t be safely softened, so the annealing absolutely must be confined to the other end — a process that’s ticklish enough with a case as long as the .30-06 and immeasurably trickier with most handgun cases and very short rifle cases.
A manufacturer friend of mine has to import his brass, and there aren’t many places he can get the particular brass he needs. He had to reject the entire shipment from one foreign company — annealed from end to end, those cases were as soft in the head as they were in the neck. (I’m inclined to suspect that the fellow who made ’em was, too.)
In days of yore, we riflemen who loaded .30-06 brass (both “straight and modified every way except with pleats and ruffles) were especially happy if we found a supply of FA Match brass (GI brass made to closer than usual tolerances, at Frankford Arsenal, for GI match loads). In March of 1957, a neighbor came back from Camp Perry with a suitcase or seabag full of once-fired .30-06 cases, headstamped FA 57 MATCH, and gave me several hundred of them. That early in the year, they had to be all from the same batch or lot, too. I gave Elmer Keith one or two hundred for his .333 OKH and his first Africa safari. The rest were supposed to be my lifetime supply for my Iver Henriksen .35 Whelen.
I started loading what I knew were reduced loads, very mild stuff, but got scary signs of excessive pressures. I reduced my loads even more but still got the same high-pressure alarms. Reducing the charge again, to produce little more than a low-smoke, low-recoil belch, did no good either. Iver Henriksen, who’d built the rifle for me, extended the throat a little — no change. Case heads still expanded enough to make the primer pockets loose — some too loose to hold primers at all.
After months of fret and frustration, we found that the case heads were too soft. FA Match brass was the best there was, so we hadn’t once thought of it as a possible source of the problem. I don’t know how much longer we would’ve puzzled over the cause of my “excessive pressures — if we hadn’t learned from some outside source that early 1957 Frankford Arsenal match brass was flawed. The explanation we got from somewhere was that to streamline case production, Frankford Arsenal had developed a process for making .30-06 brass with one draw fewer than the traditional process.
Omitting that one draw had left the brass soft — the new manufacturing process hadn’t work-hardened it enough. Safe enough for one firing, those cases were too soft in the head to be reloaded more than once. The effect of omitting one draw was the same as annealing the head of the case. Any annealing of the head is too much.
But the neck is easy to overanneal, too — get it too hot, which makes it too soft, and it’s too weak to grip the bullet as tightly as it should. There’s no good reason to fear annealing. It’s easy enough and safe enough for anyone who’s willing to be reasonably careful doing it. I shouldn’t have to say this, but experience and observation have shown that I have to say Don’t have powder, primers, ammo, lighter fluid, gasoline, or the like anywhere near. Murphy’s Law is right, as far as it goes, that whatever can go wrong will go wrong at the most inopportune time. But Murphy was a Pollyanna. Howell’s Law is more realistic: whatever can’t possibly go wrong will go wrong sooner or later.
If you plan to anneal by the old slap-dash, lick-and-a-promise methods that rely on heating the brass to the right shade of blue, practice first on ruined and junk cases before you try to anneal any you don’t want to ruin. Use cases with mouth cracks, enlarged primer pockets, incipient or partial head separations, or Berdan primers if you don’t want to load them, or those oddball cases you picked up here and there and never planned to load anyway. Pick up occasional cases for cartridges you don’t shoot, when other shooters leave them behind. Clean and polish them so you can see when the brass changes color with the steep heat you’re going to turn on them. Killing the polish with too much heat tells you you’ve gotten the case too hot.
A few paragraphs later, I’ll describe my annealing method — easy, accurate, dependable, consistent, inexpensive, convenient — which completely obsoletes the often-described but inadequate methods of holding brass in molten lead or standing cases in a pan of water, heating them to the right shade of blue, and tipping them over in the water.
Here are the principles of annealing cases:
you don’t get the brass hot enough to change its grain structure, you’ve wasted your time. If you get it too hot, you’ve ruined the case. The range of temperatures between these two points is narrow, so you need close control of heat and an accurate way to tell when it’s right. A large flame or a wide spread heats too much area too slowly. A single small flame with a sharp tip is necessary, to direct and confine the heat to the area to be annealed. A hot, hot flame gets the neck end up to the right heat quickly enough to keep the base end from getting too hot. A “hot enough” flame isn’t hot enough. “Too hot” is right. A heat sink (heat absorber) on the head helps protect this critical area from heat that roams downward while the neck heats up to the annealing temperature. A comfortable, convenient case holder must protect your flesh from heat and allow you to quench the cases quickly when they reach annealing temperature, and to replace them easily with the next case to be annealed. The neck end of the case must be annealed evenly all around, so it must turn in the flame (preferably) or be surrounded by a ring of flames directed inward. When the neck end of the case gets hot enough for the grain structure of the brass to change, the case has to be cooled down all the way, at once.
Here are the principles of annealing cases: If you don’t get the brass hot enough to change its grain structure, you’ve wasted your time. If you get it too hot, you’ve ruined the case. The range of temperatures between these two points is narrow, so you need close control of heat and an accurate way to tell when it’s right. A large flame or a wide spread heats too much area too slowly. A single small flame with a sharp tip is necessary, to direct and confine the heat to the area to be annealed. A hot, hot flame gets the neck end up to the right heat quickly enough to keep the base end from getting too hot. A “hot enough” flame isn’t hot enough. “Too hot” is right. A heat sink (heat absorber) on the head helps protect this critical area from heat that roams downward while the neck heats up to the annealing temperature. A comfortable, convenient case holder must protect your flesh from heat and allow you to quench the cases quickly when they reach annealing temperature, and to replace them easily with the next case to be annealed. The neck end of the case must be annealed evenly all around, so it must turn in the flame (preferably) or be surrounded by a ring of flames directed inward. When the neck end of the case gets hot enough for the grain structure of the brass to change, the case has to be cooled down all the way, at once.
I prefer to anneal cases before I modify their forms, especially if their new shape is going to be drastically different from the original. Some handloaders neck their cases up or down, or force the shoulder back, then anneal them before they load them. The more I’m going to change them, the more I like to anneal them before I reshape them. If I’m only slightly necking them up or down, without changing the shoulder, I can probably anneal either before or after I cold-work the brass (which does harden it a bit).
Quick, uniform, consistent application of high heat is the key to good annealing. There’d better not be a live primer in the primer pocket. You just don’t know how hard you can jump or how wide your eyes can pop until you’ve cooked off a rifle primer in a small room. A friend of mine who did — and knows — and isn’t going to forget anytime soon — is emphatic about this. If the base of the case is clear, it becomes a launching pad for that rocketing primer, which you may not see again unless you ask the doctor to save it for you after he digs it out of your eye.
There’s also a good reason for making sure there’s not even a spent primer in the case you’re heating. Annealing comprises not just one but two main steps — heating and quenching. A spent primer blocks the flow of air or water through the primer vent when you drop a heated case into the quench water. I’m not sure this does any harm, but I like to have the primer vent free, just in case the free flow of air or water through it helps make the quenching neat and consistent.
Also, if there’s a “spent” primer in the case, it might turn out to be a live one when I least expect or can take much excitement.
When the brass around the mouth reaches a temperature of about 660° to 665° Fahrenheit (about 350° Celsius, which equals 662° Fahrenheit), its surface becomes light blue — and this is as hot as you want to let it get. If you let the color run too far toward the other end of the case, you can ruin the head by making it too soft. If you let the color on the neck go beyond light blue, and the shine disappears, you’re on the thin edge of ruining the case, and you may already have gone too far.
If you let the case get red, it’s a goner. Ignore published “expert” (but totally wrong) advice that tells you to heat it red-hot. Squeeze the mouth with pliers, and you’ll see how soft it is. Remember two things: shine and light blue. Anything further is too much — and even these, too far below the shoulder, mean too much heat.
But depending on getting the color just right is too loose and iffy to suit me. I prefer and recommend relying on something more dependable than personal color perception. The most reliable case thermometer I know is a 650° or 660° F temperature-sensitive crayon (called a “temp stick,” usually). More on this in a bit.
Some writers recommend using a small gas torch. Others like a pot of bullet metal to heat case necks, but the hot, small flame of a torch is the only heat source you can rely on to give you the quick, local heat you need for selectively annealing the neck — and maybe the shoulder and upper body — without heat-softening the base. The high heat is not just better than the lower heat — it’s the only practical heat. The torch also offers one critical advantage over the pot: lead puts out poisonous fumes at 900° Fahrenheit.
High heat brings the neck and shoulder up to annealing temperature quickly, while the base end is still safely cooler; lower heat lets the base end get too hot while the neck and shoulder are getting just hot enough. Therefore, safe neck annealing takes high heat and a surprisingly short time — and he who dawdles over it ruins cases. High heat is necessary to protect the base, but its rapid heating of the neck and shoulder risks overannealing the neck. You can’t depend on feeling the heat at one end to tell you when it’s right at the other end. When you feel uncomfortable heat transmitted to your thumb and fore-finger through the brass, you may have already ruined the other end of that case. Some people’s fingertips can tolerate a lot of heat, others little or none, so your wince-and-swear threshold is a poor way to tell when the case is adequately annealed but not overdone.
Temperature-sensing crayons allow close temperature control. Any well stocked welding supplier has them or knows where to get them. McMaster-Carr stocks two kinds, and I hope a few handloader suppliers like Huntington’s will stock them if there’s enough demand for them. The mark made by one kind of crayon melts at the rated temperature, plus or minus one degree. The other kind leaves a yellow mark that changes to red-brown at the rated temperature and tolerance.
The 650°F crayon, which melts at about 10°to 15°F below annealing temperature, is Number 3261K449 in my old McMaster-Carr catalog, at a nominal price of $7.80 (I say “nominal” price because McMaster-Carr charges the price that’s current when you order — sometimes less, sometimes more, usually close). Be sure to specify “crayon” when you order — McMaster-Carr also sells 650°F temperature-sensing pellets under the same catalog number. These pellets are for other applications and aren’t adaptable to case annealing. The 660°F crayon changes color at approximately the correct annealing temperature (within two degrees or so). Its catalog number is 5960K71, its nominal price $6.20 in my old catalog. Both crayons come with aluminum pocket holders.
(After this discussion appeared in my book, a number of readers reported that they’d had a hard time getting the temp stick to leave a mark on their cases. The trick is simple — begin heating the case, then mark it with the crayon while it’s warm — but not hot enough to anneal yet.)
Which crayon is better? For annealing only a short area such as just the neck and not much lower on the case, the 660° color-change crayon is probably better, technically (for a mark at the lower edge of the area to be annealed). When the color changes a bit lower down, the upper neck should be just about the right amount hotter. Annealing a longer area — neck, shoulder, and upper body, say — means there’s a wider range of temperatures between the mouth of the case and the lower edge of the annealing area. The 650° melting crayon allows a range of about 10° to 15° Fahrenheit. You could use this crayon to mark the lower edge of the area to be annealed, or the other crayon to mark the upper portion of the annealing area.
If I were you, I’d get one of each type of crayon and evolve my own system with whichever crayon I liked better. You may well find one type of crayon better for annealing some cases and the other better for other cases. And one pair of eyes may see one crayon mark change color more easily than they see the other mark melt and run, while the latter mark may be easier for another pair of eyes to see. Try both. There may come a day when the type you prefer is worn out, lost, or not available soon enough for some important annealing you want to do right now.
The simple, convenient annealing system I favor uses the threaded locking stud and appropriate shell holder from a Lee case trimmer to grip the base of the case, both for twirling the case in the tip of the flame and for absorbing any heat that may reach the base of the case while I’m annealing the other end. I like to have at least a handle on the shaft of the Lee case trimmer’s locking stud, but no handle is really necessary — just a nice touch.
The handiest thing I’ve found is an old-fashioned hand drill. My son got a cheap and chintzy one at a swap meet for a quarter, and it isn’t worth even that much for drilling. But it’s just the ticket for twirling a case in the tip of a flame, so I guess it’s worth more than a quarter after all.
Or, if you prefer a high-tech version — at the 1994 SHOT show, Ken Oehler suggested chucking the locking stud in an electric screw-driver. I’d thought of chucking it in an electric drill, but I had abandoned that idea, because the faster speed of the drill would most likely make the crayon mark hard or impossible to see well enough. Ken Oehler’s idea of using an electric screwdriver is worth looking into. I’ve never used an electric screwdriver, but the idea seems good to me — if I ever want anything fancier than the old hand drill. (Ken often comes up with good ideas. He makes the Oehler — pronounced like Taylor without the T — chronographs and personal ballistics system.)
I thread the shell holder onto the stud, insert a crayon-marked case in the shell holder, tighten the stud into the shell holder to grip the rim of the case (it doesn’t have to be tight), and twirl the neck of the case to let the tip of the flame heat the neck all the way around, at or just above the middle of the neck (or where the eventual neck will be).
An alternative method is to thread a bronze-bristle bore-scrubber brush of the same caliber as the case neck (or slightly larger) into a section of a jointed cleaning rod or directly into a wood (preferably) or plastic handle — or best of all, chuck it in a hand drill or electric screwdriver. If you don’t have a hand drill or electric screw-driver, a swiveling handle and a short pistol-length section of cleaning rod is just about perfect, especially if the handle is plastic and therefore has to be protected from the heat.
Thrust the brush into the neck of the case you’ve polished and marked with the appropriate temp-sensor crayon. When the polished brass is the right shade of blue, the crayon mark will melt or change color in response to the heat. Shove the case immediately into cold water, pull the case off the brush, and set it aside to dry. Or drop it into the water if it still feels hot.
Don’t use the mouth-support method (the brush) if you can set yourself up to use the base-support method (the Lee shell holder), especially if you’re annealing a long section of a short case. Two extreme cases leap to mind — annealing the .32 Auto case before forming it to the .22 Flea, and annealing the .45 Auto case before forming it to Bo Clerke’s superb .38-.45 Auto. For either of these and for a host of others less critical, the only safely workable method is one that absorbs as much as possible of the heat that reaches the base before the annealing area gets hot enough. Try annealing either of these by holding it in the heat with your thumb and forefinger, and you’re sure to wind up with some combination of a hot but unannealed neck, a heat-softened base, and finger blisters.
If you use the brush and have only a plastic handle for it, be sure to cool the brush thoroughly with each case you quench, or heat buildup will melt the plastic. The older RCBS wooden handle was far superior to the prettier plastic handles now current. (Lyman still sells wooden handles, I think.) If you anneal a lot of cases, especially if you anneal them far below the shoulder, get a wooden file handle from Brownell’s and adapt it to hold your bronze brushes.
Use a good-sized container for your quench water. A bunch of hot cases, even little ones, can heat up a bucketful of tap water faster than you might think it could. If you plan to load them soon, dry them thoroughly with a jet of compressed air. Make sure no droplet of moisture remains in the primer vent. The absence of a primer is obviously an asset here too.