Practical Precision Reloading
January 04, 2011
Improve accuracy without wasting time.
Bob Milek wrote for Shooting Times from 1966 through 1979. During that time he served as a contributing editor and penned articles and columns on everything from handgun hunting to handloading for high-powered rifles. He also wrote our reloading column for two years. Over the years, he also wrote for Guns & Ammo, Hunting, Handloader, Rifle, American Hunter, American Rifleman, Sports Afield, and Field and Stream magazines, and he also authored several books, including Handgun Hunting Across North America, .22 Rimfire, Centerfire Revolvers, Rifles and Cartridges for North American Big Game, and Complete Guide to Handgun Hunting.
First printed in 1978, this article still makes a lot of sense.
If you're a benchrest shooter, you've undoubtedly experienced all the little reloading variables--neck thickness, flash-hole size, and case concentricity--that combine to rob you of that elusive one-hole group.
If you're a hunter-reloader whose shooting involves sighting-in sessions and trips after big game and varmints, chances are you've never been exposed to concentricity gauges, bullet spinners, neck-turning tools, and straight-line bullet seaters. Your reloading techniques probably only involve standard presses, dies, powder measures, and scales.
For some unknown reason, reloaders polarize at these two extremes. Precision reloaders wouldn't dream of using ammo that hadn't been tested in every known detail. Many hunters, on the other hand, consider anything but case length and powder charges as wasted time.
Who's right? Both, to some extent. However, somewhere in between is a compromise that can be very beneficial to target shooters, varmint hunters, or even big-game hunters.
This compromise is what I call "practical precision reloading." It involves all the little tricks that can improve the accuracy of your rifle without including wasted time-consuming steps.
Benchrest competition has proved that most of the steps accuracy buffs faithfully follow contribute to better accuracy. But this is true only for special benchrest competition rifles. Many of these steps are wasted when reloading an off-the-shelf varmint rifle or lightweight sporter.
Which steps can you ignore without affecting accuracy? The best thing to do is look at the more important steps, then decide.
Begin With The Case
Begin with the case, where we find the biggest gap in technique between benchresters and average reloaders. If benchrest shooting is your bag, your cases may get the entire treatment--neck sizing, neck reaming or turning, trimming, primer-pocket cleaning, flash-hole reaming, and even grouping by weight. Not all steps are practiced regularly by benchrest shooters, but most are totally neglected by hunters.
The author recommends cleaning primer pockets about every fourth time you reload to prevent excessive primer residue buildup (right).
Before beginning, inspect the case carefully for cracks, splits, deep scratches, or a bright ring around the body just above the web that signals an impending separation. Some reloaders use a magnifying glass for this, but if the case has any external faults, they'll be apparent to the naked eye.
Next consider whether to full-length or neck size the cases and whether or not to ream or turn the necks. For most hunting situations, you should full-length resize. Neck sizing guarantees a more perfect fit in the chamber and works the brass less, but neck-sized cases often chamber hard. You want fast, easy chambering and extraction, especially when after big game.
If you'll be full-length resizing, make sure you maintain proper headspace. Too often a die will oversize a case and push the shoulder back. This hurts accuracy, shortens case life, and can be dangerous.
The instructions for setting most full-length dies in a reloading press call for the shellholder to bump the bottom of the die. Don't set the die this way. Set the die off the shellholder about 0.10 inch, size a case, and note how far down the neck has been sized.
Gradually turn the die in, constantly trying and inspecting the case until sizing stops just short of or exactly at the bottom of the neck. Many times this occurs as the shellholder bumps the die, but other times there'll still be space between the die and the shellholder.
Case length is important, so the author trims cases to a specific length after every firing.
Most neck-sizing dies are made so that there's no way to oversize and shove the shoulder back. However, I've run into a few that will, so check the setting on them the same way you do a full-length die.
After sizing comes primer pocket cleaning. There's considerable controversy over this. Some reloaders clean the pocket each time a case is reloaded, and others never clean them. The "never" boys are definitely wrong because primer residue will build up until the primer can't seat below the case head. This is called "high primer," and it's dangerous. In a super-accurate bench rifle, this may make a difference; however, in most rifles, even good varmint guns, you can't detect the effects of a mildly dirty primer pocket. I clean the primer pockets about every fourth time I reload.
Case priming should receive a lot of attention, and several easy-to-use tools designed to perform this one function are available.
Reaming the flash holes to the same diameter may tighten groups fired from a benchrest rifle, but I've never seen any increase in accuracy due to flash-hole reaming in the best of my varmint rifles. The same is true for chamfering the burrs from the inside surface of the flash hole and drilling slightly from the inside to get uniform flash hole length.
When a na
tional match is at stake, flash hole treatment shouldn't be overlooked. For hunting, I only check them occasionally and discard cases with unusually large or small holes.
Case length is important in reloading any cartridge. If it exceeds the maximum length, the mouth is forced into the chamber throat when the action is closed. That causes erratic and often unsafe pressure as well as subpar accuracy. I trim my cases to a specific length after every firing. Some shooters trim to a minimum and don't trim again until the case stretches to the maximum allowable length. Either method is acceptable.
To check case length, you need an accurate caliper or a special gauge. I do my trimming with a lathe-type trimmer, available from Forster, RCBS, Lyman, Bonanza, Redding, and most other reloading-tool manufacturers. But a fixed trimmer for a specific cartridge works well and eliminates the need for a gauge if you use it every time.
Neck reaming or outside neck turning to get even neck-wall thickness is a phase of case treatment that most average reloaders neglect, even though it has definite benefits for optimum accuracy. For a big-game cartridge in a sporter, the accuracy potential probably isn't good enough to benefit from neck reaming or turning. However, uniform neck thickness makes a considerable difference in an accurate varmint rifle.
I ran a limited test using a Savage 112V .22-250 fitted with a Weaver T-16 scope. It shed some light on the neck thickness question. Using Federal brass that had been reloaded four times, I loaded 25 rounds with 34.5 grains of Hodgdon 4895 behind Sierra's 55-grain spitzer .224-inch bullet. The cases were full-length resized in an RCBS die and a Redding Model 25 turret press. They were trimmed to 1.902 inches, and the primer pockets were cleaned. Priming was done with an RCBS automatic priming tool.
After reloading, the cartridges were checked with a Bonanza Co-Ax indicator. The runout varied from 0.001 to 0.0045 inch. Then I fired five, five-shot groups at 100 yards from a good benchrest that averaged 1.06 inches.
Next, I took 25 different cases of the same lot, also reloaded four times, and reloaded them using a .22-250 Lee Target Loader kit. Every step was done with Lee tools, including priming. But the most significant item was the Lee neck reamer.
Reaming was done while the case was in the neck-sizing die, and the reamer shank was held in line by a very snug fit in the pilot hole of the die. That guaranteed a straight reaming job. The powder charge and all components were exactly the same as those used in my first loads.
When the second batch was finished, runout was again checked with the Bonanza Co-Ax indicator. The rounds with their necks reamed to uniform thickness showed runout varying from 0.000 to 0.0015 inch.
I fired five-shot groups with these loads at 100 yards, and the results were very convincing. The average was 0.872 inch, a considerable reduction in size over the first groups.
It becomes even more significant when you consider that the first test was conducted under perfectly still conditions and the second with gusts crossing my line of fire at about a 20-degree angle.
Even under windy shooting conditions, loads using reamed-neck cases produced about 18 percent better accuracy. These limited tests pointed out what benchrest competitors have known for years--uniform neck thickness is important for optimum accuracy.
I recommend that you ream or turn the necks of cases you'll be using in a good varmint rifle. But there's a catch. Sometimes necks will be so thin that they don't afford a tight friction fit between the bullet and the neck. Obviously, you can't have this condition in the field. If the bullets aren't held securely, the overall length can be changed either in the magazine or in handling. The bullet may even fall or be pulled out of the case. Be sure that your reamer or turning tool won't thin the necks too much.
Case priming should receive a lot of attention. Efforts to achieve perfect primer seating have given birth to a variety of tools designed to perform only this one function. Some tools are simple and inexpensive, others are intricate and expensive. But all are superior to priming with a loading press.
Because of the mechanical advantage a press affords, you can't feel the primer seat, and you may apply too much pressure and damage the primer. The Lee priming tool is an excellent example of one that's simple, inexpensive, and accurate. I don't know of a better tool if you're going to load just a few cartridges.
But for quantity production, the automatic-feeding tools from Bonanza and RCBS are best. They're accurate, allow "feeling" the primer into place, and are fast.
Powder charging is easy, but you should use an accurate scale and a good powder measure.
Use A Good Powder Measure
Charging the case is not difficult. All you need is an accurate scale and a good powder measure. For big-game cartridges using large-grained powder such as IMR-4350 or 4831, each charge should be checked on a scale. However, charges of small-grained powders and all spherical powders can be thrown quite accurately with a good measure.
Benchrest shooters don't weigh each powder charge. They throw them through a measure. But you can bet that benchresters select accurate measures. You can do the same thing.
Seat Bullets Quickly But With Care
After charging comes bulletseating, and the accuracy clan spends more time and effort on this step than most hunters. The straight-line seating die is common, but you seldom see hunters using it. The reason: Straight-line seating dies are slow. With the case and bullet supported in the die, the bullet is seated by striking the seating stem with a mallet or forcing it down with an arbor press. The case and bullet are held in perfect alignment throughout the seating operation.
With standard seating dies in a reloading press, the bullet may cock to the side when it starts. When this happens, the bullet starts crooked and bends the neck out of line with the case. Bonanza has a 7/8x14 thread seating die that has hand-type, straight-line seaters. With this die, the case and bullet are held in tight-fitting chambers and maintain perfect alignment. I recommend it for press users.
In hunting rifles your best accuracy will usually be achieved with the bullet seated so that it doesn't quite touch the lands. Seating the bullet too deep lets it travel free, unsupported for a greater distance, increasing the possibility of tipping slightly before entering the barrel.
Seating hard against the lands, a practice used by some benchrest shooters, isn't recommended for hunting. Not only wi
ll chamber pressure be higher when the bullet starts out against pressure from the lands, but there's also the danger that a bullet will stick if you have to extract that round without firing it. The bullet will pull out of the case and fill your action with powder.
Proper press setup is vital to making good handloads. When setting up a neck-sizing die (left), you can proabably bump the die with the shellholder. If it's a full-length sizing die, a machined washer may be required between the die and the shellholder (right).
While almost touching the lands is a desirable seating depth, it's often impossible to get because of the length of the magazine. The overall length of your cartridge can't exceed the inside length of the magazine, so it's a good idea before you start working to measure the magazine of your rifle so that you know its length to determine the proper bulletseating depth.
Set Up Tools Properly
It should now be easy to choose those reloading steps that can be applied to your particular reloading needs. However, reloading press users will find all of this wasted if they fail to set up tools properly. Manufacturing tolerances in rams, shellholders, dies, and threads all combine to make it quite easy to bend necks and cases.
It's important that the die and ram, and the decapping rod unit in the die, are perfectly in line with each other. The only way to accomplish this is with the tool under a load and the ram pressing against the bottom of the die.
First, visually check alignment of the decapping rod in the die. Set it with the rod as near center as possible. Tighten the decapping-rod locknut just enough to hold it, then screw the die into the press.
Now select the proper shellholder for your cartridge and attach it to the ram. I don't lock my shellholder; I allow it to float so that it centers itself. This sounds great, but in practice there isn't a lot of floating and centering going on. Most shellholders fit snugly in the ram. Put a new, straight case in the shellholder. The fit should be loose enough to allow the case to move and center itself.
Don't forget to center your decapping rod in the die.
With the case out of the shellholder, screw the die into the press. If it's a neck-sizing die, you can probably bump the die with the shellholder. If it's a full-length sizing die, a machined washer may be required between the die and the shellholder for correct die setting. The idea is to have the ram exerting pressure on the die at the time you tighten the lockring. The coarse 7/8x14 threads on the die and in the press head have enough play that locking the ring without a load on the die often results in tipping the die out of alignment with the shellholder.
If you've followed these instructions, your ram, shellholder, and die should be in line. But you need to center the decapping rod in the die. To do this, run a case up into the die, then loosen the rod locknut. Withdraw the case far enough that the expander ball is in the neck of the case. Holding the rod under tension, tighten the locknut securely. The decapping rod should now be centered.
This procedure should be followed when setting up any die in reloading presses. The only exception is the Bonanza Co-Ax press, which features a floating die that aligns itself. However, even with the Co-Ax press, it's necessary to adjust the decapping-rod alignment.
"Practical precision reloading" means different things to different shooters. All reloading press users should take advantage of the various alignment procedures. But where the reloading steps are concerned, the choice is yours.
Big-game hunters will get the least from neck reaming, concentricity gauges, and straight-line bulletseating because the benefits of such techniques can't be realized in most sporter-weight rifles.
Varmint hunters will benefit most from practical precision reloading.
Giving attention to a few details can improve accuracy. But while being practical about your reloading, keep one thing in mind: The accuracy of any rifle can't be hurt by precision reloading. When time and money permit, take advantage of everything possible to make sure your reloads are consistently accurate.