FACTORS IN ACCURACY, Part Two: Handloads
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Factors In Accuracy, Part Two: Handloads

by John Barsness

THIRTY-SOME YEARS ago we all firmly believed that handloads shot more accurately than factory ammunition.  The gun writers of the day said this was because we could “tailor” handloads to our particular rifle, by trying different bullets and powders to see which Old Betsy “liked.”

Most of the time our handloads did outshoot factory ammunition — but after looking back on 35 years of handloading and rifles, I don’t believe it was because we tailored anything.  Instead, handloads shot better because factory ammo was as bad as the Japanese radios then flooding the market.  Like those radios, most 1960’s factory ammo was cranked out to sell at the lowest price possible, and there wasn’t any of the “premium” stuff we can buy today.  Brass and, particularly, bullets were not very uniform, and quite often were slopped together.

I know this because I possess quite a bit of old factory ammo, courtesy of a cop friend.  Periodically people arrive at his offices with old ammo left behind by their dear departed grandfather, or found in the basement when they rented a house.  If it’s interesting, my friend sends it on.  Believe me, the average ammunition we shot in the 1960’s does not compare with the fine ammunition we can buy today.  Back then a scoped bolt-action that averaged 3 shots in an inch was an absolute wonder, and this usually couldn’t be accomplished without handloading.  With factory stuff, 2-inch groups were considered about all you could reasonably hope for.

Today I routinely test factory ammo that averages 3 shots in an inch at 100 yards, and some does better, even in some very old rifles.  Which means the ammo “tailoring” tricks of the 1960’s didn’t have much to do with the superior accuracy of our handloads.  Instead most accuracy gains were due to custom bullets made by companies like Hornady, Nosler, Sierra and Speer, seated straighter than in factory ammo.

It takes more effort to beat today’s factory ammo.  In the last issue of Rifle (No. 202) we looked at the basics of accurate rifles, which mostly come down to proper action and barrel bedding, firmly seated locking lugs, and a well-mounted scope that’s parallax-free at whatever range we’re shooting.

But we left one part of the rifle out of the equation, because it directly affects handloads: the chamber.  Here we’re talking about the entire chamber, including the throat.  Exactly how the cartridge and bullet fit in the chamber/throat directly affects accuracy — and how we handload can have major consequences on that fit.

Let’s look at the body of the chamber first.  This directly affects “headspace,” a technical term for the tiny gap between bolt-face and cartridge-head after a round’s chambered.  Headspace is “controlled” by some feature of the case that keeps the cartridge from sliding too far into the chamber.  The simplest method is the rim of older cartridges like the .30-30 WCF: the rim’s too big to fit into the body of the chamber and so stops the cartridge.

Most rifle cartridges designed for bolt actions are “rimless,” which doesn’t mean they don’t have a rim, just that it’s the same size or smaller than the case body.  The .30-06 is a typical example.  Because the rim is the same diameter as the case, the steeply-tapered portion of the case called the shoulder keeps a .30-06 round from sliding too far into the chamber.

A rimless variation is the “belted” cartridge, typified by popular rounds such as the 7mm Remington and .300 Winchester Magnums.  The belt just in front of the rim was designed to control headspace in old British cartridges that had shallow shoulders, such as the .300 and .375 Holland & Holland cases.  On modern, steep-shouldered cartridges, however, the belt’s pretty much superfluous.

No matter what form the case takes, too much headspace can be dangerous.  After we pull the trigger, the spring-driven firing pin slams the case too far forward into the chamber, whereupon expanding powder gases push the case-head back against the bolt-face, stretching the brass.  Case separations can result, even on one firing, and almost certainly occur if the case is handloaded and fired again.

But even “normal” headspace can affect accuracy.  Here we’re not talking about dangerously excessive headspace, but accepted tolerances.  Slight variations in case/chamber fit can cause erratic ignition.  Some rounds chamber more tightly, others more loosely, which varies how consistently the firing pin ignites the primer.  Bullets leave the muzzle at different velocities, ending up at different places on the target, especially at longer ranges.

This slight amount of headspace “slop” is common with typical with factory rifles and brass.  Factories tend to ream chambers at the long end of accepted headspace, because the typical bolt-action .30-06 has to chamber dozens of brands of ammo, both American and foreign.  Rifles chambered for belted cases often show even more slop.  The belt theoretically controls headspace, so chambers are often cut more tolerantly, and ammo varies more widely.

Most rimmed centerfire cartridges are chambered in lever or single-shot actions.  By their very design, typical factory lever rifles don’t lock up as precisely as a typical bolt.  Single-shot rifles tend to be better, but even in such fine falling-block rifles as the Ruger #1 and Browning 1885, there’s normally enough manufacturing tolerance to prevent truly precise headspacing.

Which is where the handloader comes in.  We can fit bottlenecked cases to our particular chamber, by first firing cases in our rifle, then resizing minimally.  The case headspaces partially on the shoulder (even if belted or rimmed), reducing erratic ignition, and centers itself in the chamber, starting the bullet straight down the bore.

Resizing cases “minimally,” however, doesn’t necessarily mean neck-sizing.  I’ve fooled around with neck-sizing quite a bit over the years, and find the practice normally produces less accurate ammunition.

Why?  The body of the typical factory neck-sizing die is much larger than the case body, so there’s nothing to hold the case in alignment with the neck-sizing portion of the die.  Consequently the neck’s often resized out of alignment with the case body, a condition often made worse when the case gets pulled back over the expander ball.

Aligned, straight, concentric: No matter what we call it, making sure our ammunition’s centered in the chamber, from case head to bullet tip, is essential to accuracy.  Without straight, we can kiss small groups good-by.

The only way to find out if your dies resize cases straight is to buy a concentricity gauge.  I have two on my bench, one from RCBS and one from NECO, and use them both for various purposes, as one is generally handier than the other for particular tasks.  When fooling around with a new set of dies, one gauge or the other soon appears, because dies are almost as quirky as people.

In making straight ammo, there are better tools and methods than the average neck-sizing die.  All the full-length dies I’ve tried in the past decade size cases straight, but more often than not, the expander ball pulls the neck crooked.  Sometimes this is because the “ball” (actually a cylinder of some sort) is mounted crooked on the decapping pin.  Expander-ball/decapping-pin straightness can be measured with a concentricity gauge, and corrected with the judicious use of pliers.

Sometimes, however, even a straight expander ball pulls necks crooked.  The only solution I’ve found is to unscrew the expander, fully size the case, then screw the expander assembly back in the die and “push” it into the neck of the sized case.  For some reason, this almost always results in straighter necks.

On the joyous occasions when a new set of full-length dies sizes cases quite straightly, with no more than .002″ runout at the case mouth, I mark the die box “OK,” so I know cases can be resized without pulling the expander ball.  Otherwise the expander-ball assembly lies loose in the box, letting me know an extra step must be performed.  This is why I prefer dies with easily-unscrewed expander assemblies, such as those made by Redding and RCBS, to those that require two wrenches and some sweat to remove, like those made by Hornady and Lee.  (Both the Hornady and Lee dies usually make fine ammo, but if they don’t the only real solution is to buy another full-length die and remove the decapping pin.  Use this for resizing, the other for expanding necks.  Don’t laugh.  I’ve got a couple die boxes with extra sizing dies minus their decapping pins.)

You can also buy match-grade dies, which compensate for all of these factors.  Normally they’re neck-sizers, but with more precise bodies than standard neck dies.  I mostly use these for varmint ammo because they save a lot of time when loading several hundred rounds, eliminating lubing, de-lubing, and (usually) case trimming.  I am particularly fond of Redding’s Competition Bushing Style neck-sizing die, but Lee’s Collet Dies also work very well.

When loading big game ammo, however, I use dies just like those you can buy in any sporting-goods store.  With the above tricks, standard dies can produce cases just as straight as those sized in match dies, and the extra time doesn’t amount to much when making 40 rounds of ammo.

My big game ammo is normally full-length sized in order to chamber smoothly, but that doesn’t mean it doesn’t fit the chamber precisely.  Unless you use a special small-base die, full-length sizing doesn’t restore brass to factory dimensions.  Instead it sizes just enough for easy chambering.

If you’ve got a tight chamber, fired brass may not affect accuracy, but most of the time, fired brass headspaces more precisely and has straighter necks.  After “fire-forming” brass in your rifle’s chamber, set the dies so that the action closes on a sized case with just a slight amount of extra effort.  Many methods can be used, including specialized tools such as Redding’s “Instant Indicator” headspace comparator, or blacking the shoulder area with match or candle smoke.  I usually just run the die into the press, with the ram up, until the die butts against the shell holder.  Then I back it off half a turn and resize a fired case.  Normally this lightly-sized case takes some effort to chamber, so I keep turning the die in, perhaps 1/20th of a turn at a time, and resizing the same case until the desired slight “crush fit” results.

This firm headspacing helps center the round in the chamber, even it the case body is sized small enough for easy chambering — and not only with typical modern steep-shouldered cases, but also gently tapered rounds.  My own modest rifle collection includes a Marlin 336 .30-30 WCF, a C. Sharps Winchester High Wall .30-40 Krag, a Winchester Model 70 Classic rebarreled to .300 H&H by the Wells Gun Shop, and a couple of .375 H&H’s, a Mark X Mauser and a Ruger #1.  Chambers are both custom and factory, the rounds both rimmed and belted, but all shoot better with fired brass full-length resized just enough to allow easy but firm chambering.

Forward of the chamber body we find the neck.  This rarely causes problems, except in odd instances where brass is too thick to allow the bullet to release easily on firing.  This almost never occurs with new brass, but thick necks can develop after brass has been fired and resized several times.  Brass starts to flow forward, thickening the neck, particularly at the shoulder/neck junction.  If the neck “grows” enough, chambering a round slightly crimps the neck around the bullet.  This not only increases pressures, but does so erratically.  The normal symptoms are unexplainable fliers and occasional signs of high pressure.

Check for this condition by inserting a bullet into the neck of fired, unsized brass.  If there’s any slight hitch, the brass either needs to be discarded or the neck turned.  Bulk brass is cheap enough that I just toss cases in common calibers, but expensive brass (either off-the-shelf or in forming time) gets outside-turned.

Brass fired several times also tends to work-harden, the result of being stretched and resized.  This particularly affects the neck, because it’s sized twice, once when squeezed down, then again when pulled over the expander ball.  Work-hardening also causes erratic bullet release.  Again, I generally toss common calibers after a few loadings, but anneal more expensive brass.

The traditional annealing method suggests heating the necks “cherry-red” with a propane torch, then dousing in cold water.  But cherry-red makes the necks too soft.

The melted-lead dip method is much better, as is Hornady’s annealing kit, but I use a simpler method perfected by my friend Fred Barker.  With Fred’s method you hold the case in your fingertips, halfway up the case body, then heat the neck in the flame from a common wax candle, turning it constantly, until the case gets too hot to hold.  Drop it onto a water-soaked towel, then use the towel to wipe the case off, which finishes the annealing and gets rid of the black soot from the candle.  The Barker Method is fast, cheap, easy, and anneals just the right amount.

The next part of the chamber is the throat, or leade, where the rifling begins.  Most factory throats are cut far larger than bullet diameter, at least at the mouth of the case, the reason many handloading gurus advise seating bullets as close to the lands as possible.  Close seating doesn’t allow the bullet to turn slightly sideways in the throat before slamming into the rifling.

However, most custom chambers (and even some of today’s factory rifles) have throats only slightly larger than bullet diameter.  With these, seating the bullet close to the lands really isn’t necessary, except perhaps with light varmint bullets that have very short bearing surfaces.

A good example of a precise custom throat is the one in the .300 Winchester Magnum Charlie Sisk (400 County Road 2340, Dayton, TX 77532, 936-258-4984) just built me on an old-model Ruger 77 action (chosen over the 77 Mark II because of the tang safety and better trigger).  This rifle has a “.30-06 length” magazine that only allows bullets to be seated out to the standard .300 Winchester overall cartridge length of 3.34″.  I mean this quite literally; I’ve tried seating bullets to 3.35″ and they jam in the magazine.  The throat, however, allows Nosler Partitions to be seated out to an overall length of nearly 3.5″.  In theory accuracy should suffer, but because of the tight cylindrical throat all the handloads I’ve tried so far grouped under an inch at 100 yards.

The throat of the .300 Winchester Short Magnum (and the other WSM’s) is interesting, mostly because it doesn’t exist.  The rifling starts right in front of the chamber’s neck, which not only keeps overall length of cartridges short enough to fit in a 3.05″ magazine, but eliminates any worry about inaccuracy resulting from “bullet jump.”  This non-existent throat is one reason factory-model WSM’s of any caliber tend to shoot very well.  (It’s also why chambering a WSM in a longer action is mostly a waste of time.  A local gunsmith has already built several .300 WSM’s on Mauser and other longer-magazine actions, because the boys want to “seat the bullet out to the lands.”  But they won’t be able to seat bullets out any farther, because the non-throat won’t let ’em.  If you want to use a longer action, why not use the .300 Winchester “Long?”  It achieves the same ballistics, or slightly better, and despite what you’ve read, doesn’t kick any harder than the .300 WSM.)

The next step is the case itself.  Over the years much advice about “uniforming” cases has been printed.  I’ve tried it all, from reaming primer pockets to weighing cases to removing the little burr on the inside of the flash-hole.  All these details may have some slight effect on benchrest ammo, fired in rifles capable of one-hole groups, but even some benchrest boys have given up on most of ’em.

Why?  They don’t make any difference.  The only case dimension that seems to help shrink groups is uniform neck thickness.  Ideally, necks shouldn’t vary more than .001″ in thickness.  Before measuring, most bulk brass must be run over an expander ball to remove dents.  Otherwise you’ll be measuring dents, not brass.

All of this takes time, but you only have to do it once.  I buy most of my brass from Midway USA (5875 Van Horn Tavern Road, Columbia, MO 65203) in 100-500 round lots, and sort necks on any batch from Remington or Winchester.  The reject rate usually runs between 5-20%, and you can use the rejects for offhand practice or dummy rounds — or neck-turn them to the same uniformity as the “good” cases.

I used to turn necks, but no more.  As a general rule brass with bad necks is lopsided all the way down through the body.  It may be straight after it’s fired, but won’t be after full-length sizing.

I don’t bother weighing brass anymore, either.  Most of it’s just too uniform these days.  The first time I’ve weighed brass in a couple years was yesterday, just for this article.  The only batch that varied more than 2% was some Winchester .300 Savage brass, at 4.8% still only plus or minus 2.4%, which matters not at all in the real world.  I use the same brass for handloads in both of my Savage 99’s, one peep-sighted, the other scoped.  The peep-sighted rifle (a takedown) will average a little over 1″ for 3 shots at 100 yards, the scoped rifle under .75″.

Here are some other weighing results from recent bulk brass:

     .223 Rem. (Rem. brass): 1.1%
     .250 Savage (Win.): 0.09%
     .257 Roberts (Rem.): 1.2%
     .30-40 Krag (Rem.): 1.1%
     .300 H&H (Win. brass): 2%.

This is plain old everyday brass, the same that’s used in Remington and Winchester factory ammo, and fired Federal factory brass varies about the same.  Federal Gold Medal, Lapua or Norma brass varies even less, usually less than .05%, and you also don’t have to bother checking their neck thickness either.  I still do occasionally, though why I don’t know, since it always measures .001″ or less.

I don’t deburr or “uniform” flash-holes anymore, and very rarely ream primer pockets to uniform depth.  Most primer pockets these days are extremely uniform, varying much less than average “depth” of primers themselves, even match-grade primers.

But just to find out how much effect everything except uniform necks has on practical accuracy, I performed a experiment last summer.  My most accurate rifle is a Remington 700 in .223 Remington, with a heavy chrome-moly barrel and laminated stock.  Aside from minor tuning, it’s out of the box.  With the right load it’s a genuine quarter-inch rifle.  (Hell, it may be better than that, but I’m not.)

The experiment involved 40 rounds of experimental ammo.  All the brass was once-fired Winchester, shot in the same rifle on a recent prairie-dog shoot.

Twenty of the cases were perfectly matched.  They weighed within .2 grain of each other, had their primer pockets and flash-holes uniformed and deburred, and were selected for necks within .001″ uniformity.

The other 20 cases were only selected for .001″ necks.  They weren’t weighed, and their primer pockets and flash-holes were left as-is.

All 40 cases were resized and decapped in a Redding Competition Bushing-Style neck die.  Then their necks were trimmed in an RCBS bench tool, then carefully deburred so there wasn’t any ridge either inside or outside.  Primers were CCI 400 Match, seated using an RCBS hand tool.  Then 26 grains of Ramshot TAC was measured into each case, and 50-grain Nosler Ballistic Tips seated.

I waited for a very calm day to shoot.  The barrel was cleaned to bare steel beforehand with JB Compound, and I fired 2 fouling shots with Winchester factory ammo before testing.  I started with the “uniformed” loads, shooting a 5-round group, aiming with a 6-24x Bausch & Lomb Elite 4200, set on 24x and adjusted to eliminate all visible parallax at 100 yards.  After letting the barrel cool, I shot a 5-shot group with the random brass, then let the barrel cool again.  Groups were alternated between the uniformed and random brass until all 40 rounds were gone.

The results?  The entire average was right around .25″, the smallest group just under .2″, the largest just over .3″.  The average difference between the two “lots” was a few thousandths of an inch — in favor of the random brass.  Now, maybe if I shot 100 groups the uniformed brass might have done better.  And maybe not.

Such results are admittedly unusual, and almost solely due to the most important factor in accurate handloads: the bullet.  The Ballistic Tips had all been run over one of Verne Juenke’s Internal Concentricity Comparators.  About 1 in 5 tested perfectly enough for my experiment; 5-shot groups fired randomly selected bullets from the same box average between .5″ and .75″ with the same load.  But “perfect” Ballistic Tips shoot better than any other bullet I’ve tried in this rifle, even benchrest bullets that have also been run through the Juenke machine. I cannot emphasize how much this machine has changed the way many shooters look at accuracy.  Before using the Juenke machine extensively, I believed that certain rifles “liked” certain bullets better.  Like most shooters, I’d try different powders in order to get a desired bullet to shoot better — and sometimes even a different primer.  This didn’t work very often.  Now I know why.  Without good bullets, uniform neck thickness and consistent ignition all the rest of it doesn’t amount to a pile of popcorn.

Today finding an accurate load is much simpler.  I carefully resize some neck-sorted, fired cases, charge ’em with an appropriate powder or two, then seat some Juenked bullets and go to the range.  If the rifle’s set up correctly, almost every load shoots acceptably.

Sure, different powder charges can result in smaller groups, and very occasionally a powder just doesn’t agree with a certain bullet.  One recent .300 H&H loathed IMR4350 with 180-grain bullets, and one batch of .22 Hornet cases needed their primer-pockets reamed.  But 85% of the time, I find an accurate load on the first try, without all the nit-picky stuff we’ve been led to believe makes a difference.

Of course, very few of us own Juenke machines.  I believe the existing total is around 500 — but they’re already making a difference in the bullets we shoot.  Swift’s Sciroccos are made with a Juenke machine, and match-grade bullets from other companies get spot-checked over them too.  I’m guessing they’ll be used in the manufacture of more bullets in the near future.

One thing I’ve found through the use of the machine is the fatter the bullet, the less difference small manufacturing variations make.  It’s a lot easier, for instance, to make a concentric .30 caliber bullet than a balanced .25 caliber bullet, one of the reasons many .30 caliber cartridges have a reputation for accuracy.  But the most consistently concentric bullets are those of .35 caliber and up.  In fact, I rarely test any bullets of .35 caliber or more that don’t check out essentially match-grade.  Which is why so many .375’s and .416’s shoot little tiny groups — if their owners can take the recoil.

But even if my Juenke machine disappeared tomorrow I’d waste less time in my handloading.  Trying a half-dozen powders in hope of getting a certain bullet to group, reaming primer pockets, weighing brass — all those things have become obsolete around my loading bench, because accurate handloads mostly boil down to starting a good bullet straight down the barrel.



Reprinted from HANDLOADER magazine with permission from Wolfe Publishing Company, 2625 Stearman Drive, Prescott, AZ 86301, 1-800-899-7810, www.riflemag.com.


John’s new book Modern Hunting Optics and other great stuff can be ordered online at www.riflesandrecipes.com.