Getting the Most out of Your Ammo
A quick review of the various reloading forums on Facebook, and other gun forums, will reveal that there are tons of misinformation being put forward as valid reloading information and techniques. I enjoy a good conversation with other knowledgeable hand loaders, but I find most of my time is spent correcting such misinformation. Sadly, some of it is nothing short of dangerous. So, the purpose of this piece is to slay some of those dragons, and get solid tested methods out there to help novices and intermediate hand loaders improve their knowledge and improve their techniques.
Of all the issues that I see problems with, proper case sizing is probably the easiest to fix, and the least understood.
Buy a box of dies from any maker, and odds are that the instructions that come in that box are at least partially wrong. That's because they are written for the lowest common denominator, meaning new users who have never reloaded before. The problem is that the way they tell that new user to set up the dies is a one size fits all approach that teaches bad habits that are extremely difficult to break later on.
We all know that to reload a cartridge, the basic steps are to resize the case, remove the old primer, put a new primer in place, charge the case with powder, and seat a bullet. Seems pretty simple, right? Well, the devil is in the details.
The purpose of reloading is to fine tune the ammunition for best performance in the particular firearm it is used in. So, you want the case to be the best fit possible in the chamber. The die box instructions tell you to raise the ram, then screw the sizer in until it touches the shell holder (or shell plate). Some will go further and tell you to lower the ram and give the die an additional quarter turn, then tighten the lock ring to lock everything down tight. Well, 99.9% of the time, you've created a situation that will result in the failure of your cases much faster than necessary. Why? Because doing it that way introduces excess head space into the process. That allows the rear of the case to stretch on firing, and will thin the case wall over time until the back half of the case breaks off when you try to extract the fired round.
The proper way to size cases goes by several names. Bump sizing, partial full length sizing, etc. What it amounts to is only sizing the case enough so that it feeds and functions through the chamber reliably, yet fights the chamber as closely as possible. That promotes long case life and better accuracy.
To set up your sizer for this method, you need a tool called a head space gauge, and a decent caliper. The base part of the gauge attaches to one arm of the caliper, and the proper collet attaches to the base. Close the caliper and zero the readout. The jaws will be approximately two inches apart with the mounted gauge fastened on one side between them. To use, you take a handful of fired cases from the rifle, and insert each case between the jaws, with the neck inserted into the collet. Close the jaws, and the readout gives you a measurement from the base of the case to the midpoint of the shoulder. That length corresponds to the distance from your bolt face to the midpoint of the shoulder in the chamber. That is your cartridge head space Write that down, and measure the remaining cases the same way. Add up those measurements and average them. This will cancel out minor variations due to brass hardness and is the baseline for your rifle as far as head space goes.
Now, lube up those cases and run one up to the top of the ram stroke. Screw the sizer die down until it makes contact with the case. From this point on, you'll be making small sizing increments and measuring the case each time like you did before. Only this time, you'll see that the length gets shorter. That's because you're 'bumping' the shoulder back a bit at a time (hence the name 'bump sizing'). The idea here is to bump the shoulder back about .003” or slightly more (to allow for brass spingback). Go slow so you don't go past where you want to end up, but when you're done you average the measurements just like you did before. The final number is your sized cartridge head space At this point, run a sized case up into the die to take up thread slack, and lock down the die so it doesn't change. That's all there is to it.
The final check is to chamber a sized case in the rifle. The bolt should close and lock into battery without any more effort than a factory round does, but it will have a much better fit, and you won't have to worry about head separation failures.
The Hornady Head space Gauge kit comes with the base unit, and five collets of different diameters that cover 98% of existing bottleneck cases. It sells for about $40 and I consider it one of the most useful tools for the loading bench you can own. All the parts are precision machined for consistent results every time.
Another method is essentially the same thing, but I call it a blacksmithing method. To do it, you need to find a straight wall pistol case that when placed over the neck of the fired case, the mouth hits more or less in the middle of the shoulder. From that point it works just like the Hornady gauge. However, remember to make sure the case mouth is even on the pistol case, make sure both ends are flat against the caliper jaws when measuring, and store that pistol case in your die box, so you can use the same one every time for consistency. The readouts in the process are relative and don't matter specifically; all you're interested in is that .003” difference between fired and sized.
Some of the things that can mess you up here are easily solved. For example, when you measure fired cases, make sure the primers are either out altogether or below the surface of the case head. A high primer will cause an error in your measurement. If the brass is work hardened, it doesn't always size enough on the first pass. If you're not getting your .003” bump, either anneal your brass and resize, or size each case a couple of times by rotating the case part way and running it back up into the sizer.
Another of the more common problems encountered by inexperienced reloaders is proper primer seating. The primer, for safety reasons, must be seated sufficiently deep that it is a couple thousandths below the face of the case head when you run your finger over it. Otherwise, you will have ignition problems, and in some cases even out of battery firing, or slam firing.
Most load presses have some sort of mechanical mechanism built into them to seat new primers during the reloading process. Depending on the brand of press, it may be a good system, or it may have issues. For example, some of the Lee presses tell you not to use certain brands of primer in their primer feed tubes because they have a tendency to set off the whole tube at once. That's not something you ever want to experience.
Or, you can seat primers manually in a hand held priming tool, as I and many, many others prefer. The advantage to the manual method is that you have much better control over the process, and a much better feel as the primer seats, so you don't over pressure them and damage the priming pellet. The leverage on a press is so great, it is difficult to tell in many cases when the primer is seated just right. I've been manually seating primers for 40+ years and can count on one hand the problems I've had related to seating them. If you do use the press, learn to get get the best feel for best results.
Whatever method you use, it requires that the primer pocket is properly prepared. Military cases are almost always found with primers crimped in place. This is to prevent jams from backed out primers in machine guns. But, in order to reprime those cases for future use, you have to remove the fired primer and the crimp from the primer pocket rim. Depending on how the crimp was applied, that can be easy or a real pain in the backside. You also find many civilian cartridges that use a crimped primer.
There is an ongoing battle among reloaders as to which method of removal is better, swaging or reaming. Swaging is probably easier, but sometimes it doesn't always move the brass enough out of the way. Then you end up reaming them anyway, so that's why I just ream them from the jump and get it over with. To do that, you need a reamer bit that fits either in a handle like a screwdriver, or that you can chuck up in a bench drill press. The Hornady set has a small bit and a large bit, and has a handle, but you can also use them in a drill press, which is what I do. They also have a built in shoulder to prevent you from cutting too deep into the pocket.
People blacksmith all kinds of ways to remove crimps, with a wide variety of tools that are not designed for that job, and that's being charitable. A good reamer bit is not that expensive, and does the job right from the start, so don't use the jerry rigged methods. I've seen guys use a chamferring tool to do it, and end up creating a bevel on the edge of the pocket that led to primer blowouts later on that damaged the bolt in the rifle.
It amazes me on a regular basis how something as simple as seating a bullet can get so screwed up. This is probably the third most problematic thing you see in the forum discussions. For this to be successful, you have to make sure the inside diameter of the neck is correct for the caliber you are working with. This has a lot of implications in the areas of neck tension, crimping (or not), and damage to the case that affects feed and function.
On average, the inner diameter of the case neck should be 0015-.002” smaller than the diameter of the bullet so that you have sufficient neck tension. The expander button in the sizer die should be measured and should be sized appropriately for that to take place. If it is too fat, then you won't get good tension and that can result in bullets walking out of the case under recoil, or getting pushed deep into the case on feeding. Either one can be extremely dangerous under the right conditions.
Another serious problem is collapsing the neck and shoulder into the case body if you have too tight a neck. That can be caused by actually having too tight a neck, but also by not chamferring the case mouth sufficiently or at all. The latter is a frequent occurrence when seating flat base bullets. Boattails usually will slip right into the neck because of the taper, but not always. So, take a chamferring tool and apply a small bevel to the inside case mouth. Don't get carried away and bevel it so much that you create a cookie cutter, however.
If you leave a sharp edge on that case mouth, it will have a tendency to dig into the body of the bullet jacket, and that can cause the entire bullet/neck/shoulder area to collapse into the body. It doesn't take much either. When your cases are sized for minimum cartridge to chamber fit, increasing the diameter of the shoulder/body junction by even .0005” can prevent the round from chambering. You may not even be able to see it, so it can be a real bear to figure out what the problem is.
Another seating issue that is seen frequently is lines engraved around the bullet ogive, or bullet noses crushed during seating. This is due to improper fit of the seating plug to the bullet profile. Hornady makes seater plugs for their dies that fit their specialized bullets. I would imagine other die makers do the same. Those plugs will eliminate the ring left on the bullet from seating and better support the bullets in question. Many die sets come with a sort of universal seater plug, and can really mangle certain bullets. For hollow points that have a jacket edge that covers the lead core, or the exposed lead is flat, use a flat faced seater plug. That will keep the bullet straight as it enters the case, and prevent damage to the lead.
Another method that works, but that is somewhat messy to accomplish, is to use either a stick of sealing wax or epoxy to build up an existing plug to fit a bullet nose that is being damaged with the regular plugs. Melt the wax in a degreased seater plug, and while it is still hot, push a bullet nose into the soft wax and let it harden. Trim the edges so your plug fits inside the seater die. Be sure to use a release agent if you use epoxy so you don't end up glued up solid. Depending on how much use you give it, you may have to redo it every so often. The best way, of course, is to get the proper plug from the die maker if at all possible.
This topic probably generates more posts, more arguments, and more pure BS than any other topic in the various forums. I will say right up front, I am NOT a proponent of crimping, except in certain specific instances. I think my reasons for that are valid, reasoned, and based on fifty years of experience in loading dozens of rifle and pistol cartridges.
A crimp is a constriction of a case where it meets the bullets to keep the bullet from moving for some reason, but not to make it tight in the case. In certain instances its is required to prevent bullets from moving under recoil such as in a tube fed magazine where the rounds are under spring pressure, or keeping the bullet from being pushed back into the case on feeding in a machine gun. In pistols, a roll crimp is meant to keep the bullet from moving long enough for the powder charge to get a good start.
Most people think that you have to crimp bullets in bottleneck rounds to make sure the bullet is tight in the neck. Nothing could be farther from the truth. As I said earlier, neck tension is the mechanism used to hold the bullet, and is accomplished by proper sizing. If a bullet moves in the neck after seating, applying a crimp isn't going to fix anything, and will make it even worse in terms of accuracy. Testing neck tension is pretty easy. Put the point of the bullet against a soft pine board section, and lean on it with your body weight. If it doesn't move, you've got great neck tension. Stop there and leave well enough alone. If it moves, start measuring expander button diameters, inside neck diameters, bullet diameters, and so on. You should have a minimum of .0015” less inside neck diameter than bullet diameter. If the expander button is too fat, chuck your button spindle into a drill press, spin it up and take a strip of fine crocus cloth to the button and skinny it up to get to your desired diameter. Use a light touch, and don't alter the shape of the button. You just want to reduce the diameter a tiny bit where it meets the case neck.
Once in awhile the die itself is not cut right. If the neck is too tight, it can be opened up by a good machinist. If its too big, the die maker will have to replace it. Another alternative is to use a collet die that allows you to adjust those dimensions with inserts to get the sizing you want. Be prepared to drop some cash if you go that route.
One of the most frequently recommended tools is the Lee FCD (Factory Crimp Die), which is supposed to apply a factory type crimp to rounds put through it. Most people don't use it correctly though. The worst thing you can do is try to size a case and apply a crimp after you've loaded it. Generally, all that is accomplished is that you ruin whatever neck tension you had. I've seen guys with perfect neck tension totally ruin it by applying a crimp after seating. Also, most people try to seat and crimp at the same time. The experts will tell you to seat and crimp in separate passes. If you feel you have to crimp, use a collet type crimp die, and crimp in a separate pass.
But, if you take the time to make sure you size right, and have proper neck tension, you won't ever need to crimp. You can thank me for that later.
This is where the rubber meets the road. You can do everything else right, but poor load work up will kill any chance you have of getting a good result from your ammunition. You have to choose the right powder, primer, charge weight, and bullet to get the results you want. You have to understand the relationships between barrel, bullet, pressure, head space, and type of rifling, among others that have an effect on the end result. This is the part where you create the magic.
Loading manuals simplify a lot of this for us, by making recommendations on powder type for any given bullet. Bullet and powder makers have the resources to pressure test their data so that data is safe for us to use, relatively speaking. But, loading manual data is a guide, not written in stone. Every rifle is different, so what works in one may not work in another just like it. The process is the important thing here in finding out what works in your rifle. In graph form, it would look like a bell curve. The majority will be under the center bell part of the curve, but there will also be some that fall to the side at either end. The first thing to determine is which family of powders is appropriate in terms of burn rate. Too fast, and pressure builds dangerously. Too slow, and you can't get enough in the case to reach your target velocity. We generally classify cartridges into categories based on case capacity, and within each category by bore diameter.
So, we find small rifle (usually under 30 gr. Capacity), intermediate or medium (30-45 gr) and large or standard rifle (45-65 gr). Magnum rounds tend to be 70 gr or higher. Within each of those groups we arrange them by caliber. The smaller the caliber, the slower the powder burn rate is for that group. So, there is a group of suitable powders that shifts to the slower side as case capacity increases. Take the .223 Rem for example. It has a case capacity of approximately 25 gr., but the bore diameter is only .224” so the powder choices are going to be relatively fast overall, but within that group toward the slower side of things. Take the same case, and open up the neck to a larger caliber, and appropriate powders will need to be a bit faster to compensate for the larger diameter. Bullet weight also plays a role here. Lighter bullets need faster powders so that the powder gas is generated fast enough to keep pushing the bullet consistently.
As you move up the ladder in case capacity and caliber, you'll find powder burn rates tend to be slower as well. Bullet weight increases as caliber increases, so powder burn rates must slow down to keep pressures within limits, and you have to use more powder to overcome inertia of the heavier bullets. Most manuals contain a burn rate chart that lists powders by relative quickness or burn rate. The very fastest are used in handgun applications, and get progressively slower as you move to the right. Keep in mind though, that burn rates can change position up or down depending on application, so you should only use such charts as a means of 'getting you in the ball park'. For example, if your favorite powder becomes unavailable or discontinued, the chart can show you similar powders that might be used as a replacement, but you will still have to start over and work up your load with the new powder.
When choosing a powder, use as many sources of information as you can to determine which is suitable for your application. For a hunting load, you would tend to go with one that delivers maximum velocity for the bullet you want to use. For target work, you don't necessarily need the speed so a medium burn rate that gives moderate velocity and better accuracy is more appropriate. Whichever way you go, your manuals will give you a basic list of suitable powders for whatever application you are aiming to fill.
Once you've decided on the powder, you want to pick an amount to start testing. If you have a good amount of experience with a particular cartridge, you can start in the mid range between a starting load and a max load. That will speed up the process, without putting you into dangerous pressures. Work up in .3 gr increments to find the max limits for your rifle. If you are completely new, start with the recommended starting load for that bullet and powder, working up in .3 gr increments to give yourself a chance to observe how the round behaves as you increase the charge. Its also a good idea to chronograph your loads as you go, and to graph them as well. The graph gives you an easy visual tool that shows the relationship between charge weight, velocity, and pressure.
The increment you use is important here. There is always a certain amount of variation in velocity for a given charge. Five identical charge weights will likely generate five slightly different velocities. So, you want your increment to be big enough to stay outside that window of variation, but not so large that you skip over an accuracy point, or jump over the pressure line inadvertently. For case capacities under 60 gr (.30-06 for example), .3 gr is nearly perfect. Above 60 gr, .5 gr will work well in most cases.
What you will quickly notice is that for every .3 gr increase in charge weight, you get roughly equal increases in velocity. The line on the graph will be more or less a straight line from lower left toward upper right. As you approach Delta (the point at which adding more powder only increases the pressure but not the velocity), the speed added between increments becomes less. The data points get closer together. When you reach Delta, you'll notice the line goes more or less flat or horizontal. At that point, back off to the last increment that had a normal increase and call that your Safe Maximum.
As I said earlier, every rifle is different, so the Delta in Rifle A may be different than Rifle B, even is they are identical make, model, and caliber. So, as you go through this process, remember that the Delta in your rifle may be higher pressure than the top load listed in the manual. You'll have to decide, after evaluating other pressure signs, if that is too much. Some rifles will never reach Delta, and pressure will keep increasing until something gives. If you encounter such a rifle, use the manual max load as the limit especially if there are other signs of high pressure. In fifty years, though, I've only seen two rifles like that. Most will give clear indications when you've exceeded the limits, before things get dangerous.
While I'm running test loads looking for the pressure limit, I usually shoot three rounds at each step to give me some idea of basic accuracy. Most rifles will exhibit two accuracy nodes. The one most people look for is the high node that is close to the max velocity. There is also generally a low node at a point somewhat below that. If you can identify those, you can start tinkering with the charge in .1 gr increments up or down, and tinker with seating depth, etc., to fine tune things. Depending on what your intended use is, it may be accurate enough without that. For example, a hunting load needs accuracy that is sufficient for hitting the kill zone on a deer, which is typically a 12” circle. A benchrest shooter, on the other hand, is chasing that fabled one hole group, and will expend a lot of work trying to get the load tuned to do that. My point here, is don't waste time tinkering if it already meets your necessary standard.
Sometimes, finding the node can be a real bug hunt, and sometimes you may never find it. That can be because of a number of things. The rifle may not like that bullet/powder combination, or you may need to start with a perfectly clean barrel (this is common with monolithic bullets). The type of bullet can be the cause because some rifles prefer flat base bullets to boattail bullets, and so on. I've encountered a few rifles that just couldn't be made to shoot more than mediocre no matter what I tried. All you can do then is either rebarrel it, redo the bedding, or just get rid of it. It depends on how much time and money you want to invest getting it to work right. With a little luck, and good records, you'll find the load you want. Take pride when you do, you've earned it.
Once you've got your finalized load, shoot several five shot groups to verify the repeatability, and chronograph the final load so you have good velocity to use for figuring external ballistic tables. Some guys love the process, and are always trying new powders and bullets. I did that quite a bit when I was younger, but have long since decided that I enjoy the shooting more, so I work up a specific load for each rifle, get it dialed in, and that's what I use from then on. I've got enough experience that I know what I want it to do, so I start out with that in mind. I don't have to experiment any more. Kind of a variation on the old idea of 'beware the man with one rifle, he just might know how to use it.' Each of my rifles has a specific load and I know exactly what I can and can't do with it.
Reading Pressure Signs
One of the toughest things to learn is how to read pressure signs. There are a lot of things that can cause false positives, and lead you down the garden path, so to speak. You have to take information from a number of sources to eliminate false positives, which requires a certain amount of skill at troubleshooting. If you don't, you'll end up all over the place trying to fix problems than may not even exist.
First, eliminate the primary cause of false positives. That is excess headspace. Excess headspace allows the primer to back out of the pocket when you fire to take up the space. The firing pin drives the case forward until the shoulder hits the chamber shoulder. If there is too much headspace that leaves a gap between the case head and the bolt face, and that allows the primer to back out on firing. As pressure of the main charge increases, the case head stretches to the bolt face, reseating the primer. That makes the primer look like pressure is too high by making it flat and removing the radius at the edges of the cup. This will happen even if the actual pressure is well under the max limit. This can happen in bolt rifles, lever guns, and the AR. Split necks and cracks in the shoulder and body can also be caused by excess headspace.
In bolt rifles, pay close attention to how much effort is needed to lift the bolt handle after firing. If that effort is noticeably higher, that's likely due to excessive pressure. You can encounter the same sort of thing in lever actions as well. If it takes more effort to extract the case, that can be high pressure, but it can also be a rough chamber or one with tool marks that allows the case walls to sink into the marks and act like a screw thread.
In ARs rough chambers can hold the case too long so that the gas actuated bolt can't pull it out, or the extractor rips a chunk out of the rim. That's not necessarily a pressure issue, but it might be in some cases. The remedy is to polish out the chamber while not removing any metal. Same thing in a bolt rifle. Excess pressure can also force the bolt carrier to cycle so fast it overrides the spring pressure in the magazine preventing pickup of a new cartridge, commonly called over gassing. Its easy to tell in an AR if you're overgassed simply by watching where the ejected case goes. If they eject at about 4 o'clock (the muzzle is 12, shooter is at 6) and out to about 5 ft, then gas pressure is correct so your load is probably not excessive.
So, if you've checked things out and don't have any of those things going on, what does indicate high pressure? Primer appearance is important. Its OK if they look a little flat, as long as the edges still have a bit of radius. Also look closely at the case head. If you see a bright circular spot, that means pressure is forcing brass into the ejector hole in the bolt face. When you open the bolt, the brass that has extruded into the hole is then scraped off, leaving a shiny spot. If you have a scrape mark that follows the curve of the rim on the case head face, that's a swipe and is caused by high pressure. Those two thing together mean you've gone well past the limit on pressure. Another thing to watch is the primer pocket. If pressure gets high enough, it will expand the case head, allowing the primer to fall out, or it will leak hot case around the edges blackening the brass. Other indicators are a crater or ridge around the firing pin indentation. That can be caused by an overly large firing pin hole in the bolt, but if that isn't the case, its due to pressure. In extreme cases, you might get a pierced primer, or an edge blowout of the primer cup. That allows gas cutting of the bolt face, and can ruin a good bolt in short order. If that happens, combined with other signs, you've seriously exceeded max limits.
The bottom line here is to eliminate those things first that can give false positives. Reading pressure signs is somewhat akin to voodoo anyway, so making it as uncomplicated as possible makes troubleshooting much, much easier.
Chronogaphing Your Loads
Chronographs are an essential tool in the handloading game, but you can get by without one. If you chose to not get one, you are limiting yourself to a lower level of performance. There are millions of people who are perfectly satisfied to use the load data in their manuals, and as long as they get their deer every year, they aren't too concerned about the rest. But if you do want to know more about your rifle, and your loads, and make the best ammunition you can, once you use one you'll wonder how you ever got along without it.
There are three basic types. The most common is the sky screen type where the bullet passes over a pair of sensors that are triggered by the shadow of the bullet as it passes, and as you might guess that makes the weather a big factor in using such units. They vary in price from just under $100 to several hundred. The best of such is probably made by Oehler. The next type uses magnetic resonance to read the passage of the bullet. MagnetoSpeed is the primer example of those, and runs around $175 to $375 depending on model and features. They are impervious to variations in sunlight and weather, and don't have to be set up in front of the bench, which is great for use at a public range. The newest type is doppler radar. The LabRadar unit is a civilian version of the big machines used by the bullet makers like Hornady. It gives a wealth of data that can't be obtained easily by any other system, but they are expensive. Last price I saw was about $500.
So what does a chronograph do for you? The most obvious thing is that it tells you the velocity of your bullet at the muzzle, or close to it. The sky screen type is usually set up so the midpoint of the sky screens is 15 ft. from the muzzle, but a little math will correct that to true muzzle velocity. The magnetic and radar types don't need correction. Once you have that velocity, you can plug it into ballistic programs that calculate exterior ballistic charts for things like mid-range height, bullet drop, and zero. If you know your bullet's ballistic coefficient, such tables are remarkably accurate.
But a chronograph can also tell you where the Delta point is to help determine max pressure by graphing the data points. It can also reveal erratic ignition. If your data points aren't lining up in a more or less straight line, your charge is not burning consistently, or it may be slow and then ramp up very fast. If you couple chronograph readings with pressure trace equipment, the information you get can tell you of potential problems with secondary pressure spikes and other things. A good chronograph also calculates extreme spread, and standard deviation numbers which play a part in shot to shot consistency and accuracy. It goes without saying that you should keep batteries fresh, and always carry a spare set just in case.
In the old days before chronographs became cheap enough for the average shooter to own one, you really had nothing but trial and error working for you to find good loads. You spent a lot more time, effort, and powder and bullets figuring out the best loads. A good chronograph can often give you enough information in one session to get the job done in one pass. For example, it would take me a minimum of two trips to the range, and sometimes three, to get the information I needed for a solid load workup when I was using my Shooting Chrony F1 Master sky screen unit. The data I got was solid, but it was time consuming having to wait for other shooters for the line to be clear, or for the lighting to shift, and so on. When I got my MagnetoSpeed Sporter, I was able to test loads for four different rifles in one afternoon, and didn't have to worry about other shooters slowing me down, or for changes in lighting. And, I was able to save and transmit each data string to my smart phone, and then email it to my home PC. No more lost data. That one first trip with the MagnetoSpeed, saved me at least three other trips, time, and gas. That made it worth every penny.
If you can't afford one of those, however, a few pointers for the sky screen type are in order. Be sure to get the type that has a separate readout on the bench. That makes the data gathering much, much easier. If its too bright, with or without a lot of clouds flying by, have something along you can use like photographer's scrim filter. You place the scrim over the top of the sky screens like an awning, and the translucent scrim makes the light even and homogeneous before it gets to the sensors. If you use a camera tripod to mount the chronograph you can also rotate the tripod head 90 degrees so the sensors are out of the bright sun. I don't recommend trying to shoot groups when using a chronograph, because you're concentrating on the group instead of where the bullet is in relation to the chronograph. That's the biggest reason guys kill their chronys. So, about halfway up the rods that hold the screens over the sensors, wrap a section of the rod with high visibility orange tape. That bright orange will show up in your scope to remind you to keep the cross hairs at the right place. It will also help to center the shot between the rods so you get maximum exposure to the sensor as the bullet passes. And, finally, take a tape measure along. Make sure the center point between the screens is 15 feet from the muzzle. That makes your data consistent from session to session, and makes it easier to keep things lined up between the bench and the target area.
As brass cases are sized, loaded, fired, and sized again, etc., the brass becomes work hardened. Depending on case shape or design, type of alloy, how hot they're loaded, and heat treating of the new brass, at some point, performance will go away. The brass won't hold bullets tightly any more, splits appear in the neck, and cracks can appear in the body. Typically, you can expect a minimum of three to five reloads per case, but sometimes it can be less.
The average factory load comes from the factory with excess head space They have to size cases to fit in 99.9% of the guns made for that caliber, so they size them small enough to meet that requirement. Couple that fact with the typical die box instructions on how to size cases, and it doesn't take long to work harden cases, and even see head separation problems. Proper sizing can pretty much eliminate the separation issue, but you still get work hardening.
That's where annealing comes in. When brass is manufactured, the process of forming cases requires them to remove the stress that builds up in the alloy several times during the process. The last step is a final anneal of the neck and shoulder so the bullet is held tightly in place. Annealing removes the stress and realigns the brass crystals to do that. Every time you size, seat a bullet, and fire the round, stress builds up in the neck and shoulder and eventually prevents the case from properly doing its job.
To remove that stress, you have to heat the alloy to a certain temperature and hold it there for a certain amount of time. That allows the stress to dissipate and the crystals to realign to their original state. The temperature needed has a fairly wide range, but if its on the low end, you have to leave it in the heat longer and then heat migrates to the case head, where you don't want it. Too hot and it ruins the temper of the alloy. Typically, a temperature of 750 degrees for about 5 seconds is sufficient. There's a problem though. When the alloy heats up, it glows. Depending on the alloy mix, it can be a dull orange, a coppery hue, a reddish hue, and can exhibit flashes of yellow and green due to trace elements. The human eye does not have the discrimination power to translate those colors to an accurate temperature. You can also get different colors from the same alloy in the same batch of cases. So, that makes all the methods you'll see that are based on brass color when heated up suspect. You want all your brass to be annealed as closely as possible to the same temperature for the same amount of time.
The best way to do that is to use an automated annealing machine. Like most other specialized tools in this hobby, there are several types and price points. But basically, it must be adjustable for amount of heat, time in the heat, and feeding cases into the machine. There are do-it-yourself plans available so you can build your own for about $100 or so. Commercial models run from about $250 to a couple thousand. Most of them use propane gas to apply the heat, but the more expensive ones use electric induction, and a couple use a hot salt bath. They all work very well. It just depends on how much you want to invest. If you need to do thousands of cases on a regular basis, then one of the top line models is justified cost wise. The one I have I built from the kit plans. Not fancy, but it works, and I don't have to anneal that often.
To use, you need a bottle of Tempilaq 750 liquid. This is used to tell you when the brass reaches the correct temperature. You apply a dot of liquid to the inside of the neck, and one on the outside like you would white-out on a document. When heat is applied, the dots will change color when the correct temperature is reached, at which point you remove the case from the heat and let it air cool. With the automated units, you adjust the timing so that the case is held in the flame only as long as it takes for the dot to change. That's is typically about 5 seconds. Then the next case is rotated into the flame and you repeat. The unit has a hopper and feed mechanism that just keeps dropping cases until you're done. Its simple, reliable, and easy, and you get very consistent results.
Annealing makes maintaining good neck tension for seating much easier, and since bullets are released more consistently, accuracy is helped as well. Its worth it just for that fact alone. But the biggest benefit to annealing is that it extends the life of the case tremendously. Assuming proper sizing, a load that is good for 4-5 reloads before brass issues start to show up, can often double or even triple that amount before getting worn out. Of course, the hotter the load, the shorter the life span in general because the primer pockets generally give out long before the neck and shoulder become unusable.
Whether or not you anneal is something you have to decide for yourself. If you have access to lots of cheap brass (like .223 or .308 military), it may not be worth the effort. If you have brass that is expensive and hard to come by, or maybe even obsolete, annealing is a way to make that brass last as long as possible. In addition, if you are shooting wildcats where you have to form cases from something else, you may have to anneal as part of that forming process. If you find you need or want to, make life easy on yourself and get one of the automated machines. A commercial model that is similar in operation to the one I built from a kit is excellent quality and is called the Anneal-Eze. The price is very reasonable and its easy to use.
I've covered a lot of stuff here, and hopefully it made sense as you read it. There are other ways to do some of this stuff, but I've tried to be as practical as possible. I hate busy work, so the methods I use have to have a high degree of utility, and simplicity. Otherwise, I feel like I'm wasting my effort. I also have a tendency to analyze things to see if there's a more practical way to do it, or to get a better result. That's why some of what I've said is in direct conflict with some of the recommendations made by the 'experts'. Most of this information was well known and readily available prior to World War II, and was written about by the icons of the handloading world. The internet is a great tool, and I use it all the time, but it is also a source of a lot of garbage, an awful lot of which gets perpetuated by those who don't know any better. So, take this for what its worth. I hope you find it worthwhile and helpful.
By John Hull