The U.S. Army Marksmanship Unit published a series of reloading “how-to” articles on the USAMU Facebook page. A while back the USAMU’s reloading gurus looked at the subject of cartridge run-out and what can be done to produce straighter ammo. Tasked with producing thousands of rounds of ammo for team members, the USAMU’s reloading staff has developed smart methods for improving concentricity, even with budget-priced dies. For other hand-loading tips, visit the USAMU Facebook page.
Minimizing Runout with Standard Seating Dies
This USAMU article explains how to set up standard bullet seating dies dies to minimize Total Indicated Run-out (TIR). The loading process is described using a single-stage press since most handloaders have one. A high-quality run-out gauge is essential for obtaining consistent, accurate results.
Having sized, primed, and charged our brass, the next step is bullet seating. Many approaches are possible; one that works well follows. When setting up a standard seating die, insert a sized, trimmed case into the shellholder and fully raise the press ram. Next, back the seating stem out and screw the die down until the internal crimping shoulder touches the case mouth.
Back the die out ¼ turn from this setting to prevent cartridge crimping. Next, lower the press ram and remove the case. Place a piece of flat steel (or window glass, which is quite flat) on the shellholder and carefully raise the ram.
Place tension on the die bottom with the flat steel on the shellholder. This helps center the die in the press threads. Check this by gently moving the die until it is well-centered. Keeping light tension on the die via the press ram, secure the die lock ring. If one were using a match style, micrometer-type seating die, the next step would be simple: run a charged case with bullet on top into the die and screw the seating stem down to obtain correct cartridge OAL.
However, with standard dies, an additional step can be helpful. When the die has a loosely-threaded seating stem, set the correct seating depth but don’t tighten the stem’s lock nut. Leave a loaded cartridge fully raised into the die to center the seating stem in the die. Then, secure the stem’s lock nut. Next, load sample cartridges and check them to verify good concentricity.
One can also experiment with variations such as letting the seating stem float slightly in the die to self-center, while keeping correct OAL. The run-out gauge will show any effects of changes upon concentricity. However, this method has produced excellent, practical results as evidenced by the experiment cited previously. These results (TIR Study 2) will reproduced below for the reader’s convenience.
First, however, let’s examine run-out figures of some factory-loaded match ammunition. This should give readers who are new to TIR gauges some perspective about the TIR ranges one might encounter.
TIR Study 1: 50 rounds Lake City M852 Match 7.62mm
(168 gr. Sierra MatchKings)
0.000” – 0.001” = 2%
0.001” – 0.002” = 30%
0.002” – 0.003” = 16%
0.003” – 0.004” = 22%
0.004” – 0.005” = 14%
0.005” – 0.006” = 14%
0.006” – 0.007” = 0%
0.007” – 0.008” = 2%
TIR Study 2: 50 rounds of .308 match ammo loaded using carefully-adjusted standard dies, vs. 50 using expensive “Match” dies from the same maker.
Standard dies, TIR:
0.000” — 0.001” = 52%;
0.001”– 0.002” = 40%;
0.002”– 0.003” = 8%.
None greater than 0.003”.
Note: both samples were loaded using the O-Ring method, i.e. with a rubber O-Ring placed under the locking ring of the Full-length sizing die to allow that die to float.
These tips are intended to help shooters obtain the best results from inexpensive, standard loading dies. Especially when using cases previously fired in a concentric chamber, as was done above, top-quality match dies and brass can easily yield ammo with virtually *no* runout, given careful handloading.
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When neck-turning cases, it’s a good idea to extend the cut slightly below the neck-shoulder junction. This helps keep neck tension more uniform after repeated firings, by preventing a build-up of brass where the neck meets the shoulder. One of our Forum members, Craig from Ireland, a self-declared “neck-turning novice”, was having some problems turning brass for his 20 Tactical cases. He was correctly attempting to continue the cut slightly past the neck-shoulder junction, but he was concerned that brass was being removed too far down the shoulder.
Craig writes: “Everywhere I have read about neck turning, [it says] you need to cut slightly into the neck/shoulder junction to stop doughnutting. I completely understand this but I cant seem to get my neck-turning tool set-up to just touch the neck/shoulder junction. It either just doesn’t touch [the shoulder] or cuts nearly the whole shoulder and that just looks very messy. No matter how I adjust the mandrel to set how far down the neck it cuts, it either doesn’t touch it or it cuts far too much. I think it may relate to the bevel on the cutter in my neck-turning tool…”
Looking at Craig’s pictures, we’d agree that he didn’t need to cut so far down into the shoulder. There is a simple solution for this situation. Craig is using a neck-turning tool with a rather shallow cutter bevel angle. This 20-degree angle is set up as “universal geometry” that will work with any shoulder angle. Unfortunately, as you work the cutter down the neck, a shallow angled-cutter tip such as this will remove brass fairly far down. You only want to extend the cut about 1/32 of an inch past the neck-shoulder junction. This is enough to eliminate brass build-up at the base of the neck that can cause doughnuts to form.
The answer here is simply to use a cutter tip with a wider angle — 30 to 40 degrees. The cutter for the K&M neck-turning tool (above) has a shorter bevel that better matches a 30° shoulder. There is also a 40° tip available. PMA Tool and 21st Century Shooting also offer carbide cutters with a variety of bevel angles to exactly match your case shoulder angle*. WalkerTexasRanger reports: “I went to a 40-degree cutter head just to address this same issue, and I have been much happier with the results. The 40-degree heads are available from Sinclair Int’l for $15 or so.” Forum Member CBonner concurs: “I had the same problem with my 7WSM… The 40-degree cutter was the answer.” Below is Sinclair’s 40° Cutter for its NT-series neck-turning tools. Item NT3140, this 40° Cutter sells for $14.99. For the same price, Sinclair also sells the conventional 30° Cutter, item NT3100.
Al Nyhus has another clever solution: “The best way I’ve found to get around this problem is to get an extra shell holder and face it off .020-.025 and then run the cases into the sizing die. This will push the shoulder back .020-.025. Then you neck turn down to the ‘new’ neck/shoulder junction and simply stop there. Fireforming the cases by seating the bullets hard into the lands will blow the shoulder forward and the extra neck length you turned by having the shoulder set back will now be blended perfectly into the shoulder. The results are a case that perfectly fits the chamber and zero donuts.”
The last half-inch or so of your barrel is absolutely critical. Any damage (or abnormal wear) near the crown will cause a significant drop-off in accuracy. Here are ways you can check the end of your barrel, using a common Q-Tip.
Use Q-Tip for Barrel Inspection
To find out if you have a burr or damage to your crown, you can use an ordinary Q-tip cotton swab. Check the edges of the crown by pulling the Q-tip gently out past the edge of the crown. If you have a burr, it will “grab” the cotton and leave strands behind.
Larry Willis has another way to use a Q-Tip: “Here’s a neat trick that will surprise you with how well it works.” Just insert a Q-Tip into your barrel (like the picture below), and it will reflect enough light so that you can get a real good look at the last half inch of rifling and the crown of your barrel. In most cases you’ll find that this works much better than a flashlight. Larry tells us: “I’ve used this method about a jillion times. Q-Tips are handy to keep in your cleaning supplies anyway. This is a good way to judge approximately how well you are cleaning your barrel when you’re at the range. It’s also the best way to examine your barrel when you’re in the field.”
Coating bullets with a friction-reducing compound such as Molybdenum Disulfide (Moly) offers potential benefits, including reduced barrel heat, and being able to shoot longer strings of fire between bore cleanings. One of the effects of reduced friction can be the lessening of internal barrel pressures. This, in turn, means that coated bullets MAY run slower than naked bullets (with charges held equal).
To restore velocities, shooters running coated bullets are inclined to “bump up” the load — but you need to be cautious.
Be Careful When Increasing Loads for Coated Bullets
We caution shooters that when your start out with coated bullets in a “fresh barrel” you should NOT immediately raise the charge weight. It may take a couple dozen coated rounds before the anti-friction coating is distributed through the bore, and you really start to see the reduced pressures. Some guys will automatically add a grain or so to recommended “naked” bullet charge weights when they shoot coated bullets. That’s a risky undertaking.
We recommend that you use “naked” bullet loads for the first dozen coated rounds through a new barrel. Use a chronograph and monitor velocities. It may take up to 30 rounds before you see a reduction in velocity of 30-50 fps that indicates that your anti-friction coating is fully effective.
We have a friend who was recently testing moly-coated 6mm bullets in a 6-6.5×47. Moly had not been used in the barrel before. Our friend had added a grain to his “naked” bullet load, thinking that would compensate for the predicted lower pressures. What he found instead was that his loads were WAY too hot initially. It took 30+ moly-coated rounds through the bore before he saw his velocities drop — a sign that the pressure had lowered due to the moly. For the rounds fired before that point his pressures were too high, and he ended up tossing some expensive Lapua brass into the trash because the primer pockets had expanded excessively.
LESSON: Start low, even with coated bullets. Don’t increase your charge weights (over naked bullet loads) until you have clear evidence of lower pressure and reduced velocity.
Procedure After Barrel Cleaning
If you shoot Moly, and clean the barrel aggressively after a match, you may want to shoot a dozen coated “foulers” before starting your record string. Robert Whitley, who has used Moly in some of his rifles, tells us he liked to have 10-15 coated rounds through the bore before commencing record fire. In a “squeaky-clean” bore, you won’t get the full “benefits” of moly immediately.
To learn more about the properties of dry lubricants for bullets, read our Guide to Coating Bullets. This covers the three most popular bullet coatings: Molybdenum Disulfide (Moly), Tungsten Disulfide (WS2 or ‘Danzac’), and Hexagonal Boron Nitride (HBN). The article discusses the pros and cons of the different bullet coatings and offers step-by-step, illustrated instructions on how to coat your bullets using a tumbler.
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It’s summertime, so many folks will head to the hinterlands on prairie dog safaris. On a good P-Dog adventure, you may shoot hundreds of rounds over a long weekend. So you’ll need plenty of ammo. With these ammo volume requirements, you probably won’t have time to load to benchrest standards, and you may not have the budget for match-grade bullets. To save time you may throw (rather than weigh) your charges, or even load on a progressive press. This all raises the question of ammo accuracy — how good is “good enough”? A Sierra Bullets expert answers that question here — explaining how to efficiently load ammo for varmint work.
Ammunition Accuracy Requirements 101 — Varmint Ammo
This story based on article by Sierra Bullets Chief Ballistician Tommy Todd
I load and shoot ammunition for a living. In my duties here at Sierra I constantly test bullet accuracy for our production needs. Because of this, I shoot a variety of different calibers and cartridges on a daily basis and a large demand of this shooting is keeping the guns and loads tuned for optimum accuracy. I have a very narrow window of tolerances to maintain in order to provide our customers (you) with the most accurate bullets on the market.
I have learned many tricks and techniques over the years to tuning a load, prepping brass, and cleaning barrels to keep a gun shooting. I often utilize the things I have learned and take them to extreme levels when competing in a shooting event. I also often ignore most of these things (other than safety) and simplify the process if the shooting I will be doing does not warrant.
[One summer] I went on a prairie dog shoot in Wyoming with some good friends. The targets cooperated as did the weather with the exception of some challenging winds we experienced. We had a great time and make a lot of hits on those small rodents. When loading for the .223 Remington rifles and the TC Contender, I cut a few corners in the ammunition-loading process due to both time constraints and accuracy needed. When shooting at a prairie dog a miss is simply that, but when shooting at say the X-Ring at 1000-yard competition, a poorly-placed shot [harms your] placing in the match. Because of this, I can afford to miss an occasional shot at a varmint due to ammunition capability without worry but will not allow the same tolerances in my match ammo. For the Wyoming trip I utilized a powder measure and simply dumped the charges into primed cases that had been full-length sized and primed.
I had measured enough for length to know that while there was some variance all were under maximum length. I know there is some variation of the measure I utilized but not significant enough to warrant weighing every charge. When seating the bullets a competition seating die was used and I verified OAL on the occasional cartridge to make sure nothing changed.
This varmint ammo, with thrown charges, put TEN shots inside ONE inch at 200 yards. That’s half MOA. Good Enough? Absolutely!
The ammo produced shot under one inch at 200 yards in one of the guns I planned on taking on to Wyoming with me. [Editor: That was for TEN Shots — see above.] I knew I had loaded ammunition that was quite suitable for the task at hand which was evidenced by the number of hits I was able to make at fairly long range.
NOTE: The author, Tommy Todd, explains that, when loading ammo for F-Class matches, he uses more exacting methods. He weighs every charge and seats his bullets carefully with an arbor press. Todd adapts his methodology for his particular application. The lesson here is to load to the level of precision demanded by your discipline. READ Full Story HERE.
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A while back, Sinclair International’s Reloading Press Blog featured a “round-table” discussion of reloading techniques. Sinclair’s team of tech staffers were asked: “What do you feel is the one-most crucial step in precision reloading?”
Here are their responses (along with comments from our Editors):
Phil Hoham: “I feel that when working up a load do not go too high or too low in your powder charge. Stay away from ‘suggested loads’ you hear at the range, or on the internet. Always be sure to use a published reloading manual that presents not only minimums and maximums, but also pressure, velocity, and a proper range of powders used. Do not get distracted in the reloading process, and remain focused at all times during each step involved.”
AccurateShooter.com: Some loads presented on the Internet are OK as a starting point, but it is absolutely critical to understand that pressure maximums will vary considerably from one rifle to another (of the same chambering). For example, one 6mmBR rifle shooting 105gr bullets can max out with 30.0 grains of Varget powder, while another rifle, with the same chamber dimensions, but a different barrel, could tolerate (and perform better) with half a grain more powder. You need to adjust recommended loads to your particular rifle and barrel.
Pete Petros: “This could be a very broad topic, but if I were to pick one, it would be making sure to pay close attention, and weigh each and every powder charge to ensure that each load is exact and consistent. This is important not only for accuracy, but also for safety reasons.”
AccurateShooter.com: If you’re shooting beyond 200 yards, it is critical to weigh your loads with an accurate scale or automated system such as the AutoTrickler V3/V4. Loads that are uniform (within a few kernels) will exhibit lower Extreme Spread and Standard Deviation. And remember, even if you stick with the same powder, when you get a new powder lot, you may have to adjust your load quite a bit. For example, .308 Palma shooters have learned they may need to adjust Varget loads by up to a full grain from one lot of Varget to the next.
Ron Dague: “I feel that the most important step(s) in reloading for accuracy are in the initial case prep. Uniforming the primer pocket to the same depth to ensure consistency in primer seating is a crucial step. Additionally de-burring the flash holes, each in the same way to clean up and chamfer the inside is important. It ensures that the ignition from the primer is uniform and flows out in the same consistent pattern. Doing so will create uniform powder ignition and tighten up your velocity Extreme Spread.”
AccurateShooter.com: With some brands of brass, primer pocket uniforming and flash-hole deburring is useful. However, with the best Lapua, Norma, and RWS brass it may be unnecessary, or worse, counter-productive. So long as your Lapua brass flash-holes are not obstructed or smaller than spec, it may be best to leave them alone. This is particularly true with the small flash holes in 220 Russian, 6BR, and 6.5×47 cases. MOST of the flash-hole reaming tools on the market have cutting bits that vary in size because of manufacturing tolerances. We’ve found tools with an advertised diameter of .0625″ (1/16″) that actually cut an 0.068″ hole. In addition, we are wary of flash-hole deburring tools that cut an aggressive inside chamfer on the flash-holes. The reason is that it is very difficult to control the amount of chamfer precisely, even with tools that have a depth stop.
Rod Green: “I feel that bullet seating is the most important step. If you had focused on making sure all prior steps (case prep, powder charge, etc.) of the process have been carefully taken to ensure uniformity, bullet seating is the last step, and can mean all the difference in the world in terms of consistency. Making sure that the bullet is seated to the same depth each time, and time is taken to ensure that true aligned seating can make the load.”
Bob Blaine: “I agree with Rod. I strongly feel that consistent bullet seating depth is the most important step in creating the most accurate hand loads. I have seen the results in both my bench and long range rifles. Taking the time to ensure exactness in the seating process is by far, the number one most important step in my book.”
AccurateShooter.com: Agreed. When loading match ammo, after bullet seating, we check every loaded round for base of case to ogive length. If it varies by more than 3 thousandths, that round is segregated or we attempt to re-seat the bullet. We measure base of case to bullet ogive with a comparator mounted on one jaw of our calipers. You may have to pre-sort your bullets to hold the case-base to ogive measurement (of loaded rounds) within .003″.
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Here’a useful article by Sierra Bullets Media Relations Manager Carroll Pilant. This story, which originally appeared in the Sierra Bullets Blog, covers some of the more common ammo problems that afflict hand-loaders. Some of those issues are: excessive OAL, high primers, and improperly-sized cases. Here Mr. Pilant explains how to avoid these common problems that lead to “headaches at the range.
I had some gentlemen at my house last fall getting rifle zeros for an upcoming elk hunt. One was using one of the .300 short mags and every 3rd or 4th round would not chamber. Examination of the case showed a bulge right at the body/shoulder junction. These were new cases he had loaded for this trip. The seating die had been screwed down until it just touched the shoulder and then backed up just slightly. Some of the cases were apparently slightly longer from the base to the datum line and the shoulder was hitting inside the seating die and putting the bulge on the shoulder. I got to thinking about all the gun malfunctions that I see each week at matches and the biggest percentage stem from improper handloading techniques.
One: Check Your Cases with a Chamber Gage
Since I shoot a lot of 3-gun matches, I see a lot of AR problems which result in the shooter banging the butt stock on the ground or nearest solid object while pulling on the charging handle at the same time. I like my rifles too well to treat them that way (I cringe every time I see someone doing that). When I ask them if they ran the ammo through a chamber gage, I usually get the answer, “No, but I need to get one” or “I didn’t have time to do it” or other excuses. The few minutes it takes to check your ammo can mean the difference between a nightmare and a smooth running firearm.
A Chamber Gauge Quickly Reveals Long or Short Cases
Size Your Cases Properly
Another problem is caused sizing the case itself. If you will lube the inside of the neck, the expander ball will come out a lot easier. If you hear a squeak as the expander ball comes out of a case neck, that expander ball is trying to pull the case neck/shoulder up (sometimes several thousandths). That is enough that if you don’t put a bulge on the shoulder when seating the bullet … it can still jam into the chamber like a big cork. If the rifle is set up correctly, the gun will not go into battery and won’t fire but the round is jammed into the chamber where it won’t extract and they are back to banging it on the ground again (with a loaded round stuck in the chamber). A chamber gage would have caught this also.
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
Just a quick tip — To extract the partial case, an oversized brush on a cleaning rod [inserted] and then pulled backward will often remove the case. The bristles when pushed forward and then pulled back act like barbs inside the case. If you have a bunch of oversized case that have been fired, I would dispose of them to keep from having future problems. There are a few tricks you can use to salvage them if they haven’t been fired though. Once again, a case gage would have helped.
Two: Double Check Your Primers
Another thing I see fairly often is a high primer, backwards primer, or no primer at all. The high primers are bad because you can have either a slam fire or a misfire from the firing pin seating the primer but using up its energy doing so. So, as a precaution to make sure my rifle ammo will work 100% of the time, I check it in a case gage, then put it in an ammo box with the primer up and when the box is full, I run my finger across all the primers to make sure they are all seated to the correct depth and you can visually check to make sure none are in backwards or missing.
Three: Check Your Overall Cartridge Length
Trying to load the ammo as long as possible can cause problems also. Be sure to leave yourself enough clearance between the tip of the bullet and the front of the magazine where the rounds will feed up 100%. Several times over the years, I have heard of hunters getting their rifle ready for a hunt. When they would go to the range to sight in, they loaded each round single shot without putting any ammo in the magazine. On getting to elk or deer camp, they find out the ammo is to long to fit in the magazine. At least they have a single shot, it could be worse. I have had hunters that their buddies loaded the ammo for them and then met them in hunting camp only to find out the ammo wouldn’t chamber from either the bullet seated to long or the case sized improperly, then they just have a club.
Four: Confirm All Cases Contain Powder
No powder in the case doesn’t seem to happen as much in rifle cartridges as in handgun cartridges. This is probably due to more handgun ammo being loaded on progressive presses and usually in larger quantities. There are probably more rifle cartridges that don’t have powder in them than you realize though. Since the pistol case is so much smaller internal capacity, when you try to fire it without powder, it usually dislodges the bullet just enough to stick in the barrel. On a rifle, you have more internal capacity and usually a better grip on the bullet, since it is smaller diameter and longer bearing surface. Like on a .223, often a case without powder won’t dislodge the bullet out of the case and just gets ejected from the rifle, thinking it was a bad primer or some little quirk.
For rifle cases loaded on a single stage press, I put them in a reloading block and always dump my powder in a certain order. Then I do a visual inspection and any case that the powder doesn’t look the same level as the rest, I pull it and the one I charged before and the one I charged after it. I inspect the one case to see if there is anything visual inside. Then I recharge all 3 cases. That way if a case had powder hang up and dump in the next case, you have corrected the problem.
On progressive presses, I try to use a powder that fills the case up to about the base of the bullet. That way you can usually see the powder as the shell rotates and if you might have dumped a partial or double charge, you will notice as you start to seat the bullet if not before. On a progressive, if I don’t load a cartridge in one smooth stroke (say a bullet tipped over sideways and I raised the ram slightly to reset it) Some presses actually back the charge back adding more powder if it has already dumped some so you have a full charge plus a partial charge. When I don’t complete the procedure with one stroke, I pull the case that just had powder dumped into it and check the powder charge or just dump the powder back into the measure and run the case through later.
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The U.S. Army Marksmanship Unit (USAMU) published a series of reloading articles on its Facebook Page. In this article, the second in a 3-part series, the USAMU covers the process of loading competition pistol ammunition. The authors focus on two key elements — the taper crimp and the quality/uniformity of the original brass. If you shoot pistol competitively, or just want to maximize the accuracy of your handguns, read this article. The taper crimp tips are very important.
Loading Accurate Competition Pistol Ammunition — Part 2 of 3
Today, we resume our series on factors affecting accuracy in pistol handloads. Readers who missed Part One can visit our USAMU Facebook Page. [To read the first article in the series, search for March 28, 2018 to find that first installment, which is definitely worth reading.]
One often-overlooked aspect of handloading highly-accurate pistol ammunition is the amount of taper crimp used, and its effect on accuracy. (NOTE: this article pertains to loading for semi-autos – revolver crimp techniques involve some quite different issues.) Briefly, different amounts of taper crimp are used with various handloads to obtain best accuracy. The amount is based on bullet weight, powder burn rate and charge, plus other factors such as case neck tension. During machine-rest testing of experimental Service Pistol ammunition, many variables are examined. Among these, our Shop often varies a load’s crimp in degrees of 0.001″ when re-testing for finest accuracy.
How to Measure Taper Crimp on Pistol Cartridges
One question that often arises is, “How do I measure the taper crimp I’m putting on my cartridges?” Using the narrow part of one’s dial caliper jaws, carefully measure the case diameter at the exact edge of the case mouth on a loaded cartridge. It’s important to take several measurements to ensure consistency. Also, be sure to measure at several places around the case mouth, as case wall thickness can vary. After measuring 2-3 cartridges with a given crimp setting, one can be confident of the true dimension and that it can be repeated later, if needed.
However, for good results, one must use brass from one maker due to variances in case wall thickness. For example, the same degree of crimp that imparts a measurement of 0.471″ with Brand X brass may result in 0.469″ with Brand Y. Thus, for best accuracy, using brass from the same manufacturer is important — particularly for 50-yard Slow Fire. In a perfect world, it is better still to use brass from one lot number if possible. With the popularity of progressive presses using interchangeable tool heads, keeping separate tool heads adjusted for each load helps maximize uniformity between ammunition lots.
Brass Uniformity and Accuracy
Brass is important to pistol accuracy. While accurate ammunition can be loaded using brass of mixed parentage, that is not conducive to finest results, particularly at 50 yards. It is important for the serious competitor to pay attention to his brass – even if only for the 50-yard “Slow Fire” portions of “Bullseye” matches and practice. By segregating brass as described above, and additionally keeping track of the number of times a given batch of cases has been fired, one can ensure case neck tension and case length are at their most uniform.
Given the large volumes of ammunition consumed by active pistol competitors, using inexpensive, mixed surplus brass for practice, particularly at the “short line” (25 yards), is understandable. In NRA Outdoor Pistol (“Bullseye”), the 10-ring is relatively generous — especially for a well-trained shooter with an accurate pistol and load. However, for the “long line” (50 yards), purchasing and segregating a lot of high-quality brass to be used strictly for slow-fire is a wise idea. To keep track of your brass on the line, use a unique headstamp marking with 1 or 2 colors of marking pen ink.
Uniform Cartridge Overall Length is Important
Cartridge case Overall Length (OAL) uniformity as it comes from the factory is important to achieving utmost accuracy. More uniform case lengths (best measured after sizing) contribute to greater consistency of crimp, neck tension, ignition/burn of powder charge, headspace (rimless cartridges), etc. Cartridge case-length consistency varies noticeably by maker and, with lesser manufacturers, also from lot to lot. Some manufacturers are more consistent in their dimensions than others, and also in the hardness/ductility of their brass. Similarly, pay attention to primer brands, powder lot numbers, etc.
Consider Using a Lock-Out Die with Progressive Presses
When reloading pistol ammo with a Progressive press, we strongly recommend the use of a lock-out die, or other system that can detect double charges or low charges. If your progressive is manually advanced, the possibility of a double charge is very real — and that can have disastrous consequences.
On UltimateReloader.com website you’ll find an excellent two-part series on the function and set-up of the RCBS Lock-Out Die. This die prevents loading if a high or low powder charge is detected. The video above shows setup of the RCBS Lock-Out Die on the Dillon XL-650 progressive press.
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If you hand-load pistol ammunition, you should definitely have a case gauge (aka “gage”) for each cartridge type you reload. Caliber-specific, precision-machined cylindrical gauges perform many important functions. They will instantly reveal if your rounds are too long or have excessive headspace. They will also show if your case is bulged or otherwise too fat to chamber easily. You can use the gauge with sized brass as well as loaded rounds.
Case gauges are a “must-have” for anyone loading handgun ammunition, particularly if you crank out large quantities of pistol ammo with a progressive press. An oversize round can cause a misfeed, jam, or other problem. That can ruin your day if you are in the middle of a shooting match. If you are relying on your handgun for self-defense, the last thing you want is a malfunction of any kind. This Editor personally runs every pistol round through a gauge before it goes into the ammo box.
UltimateReloader.com Video Shows How to Use Pistol Case Gauges:
Our friend Gavin Gear of UltimateReloader.com has prepared an excellent video that explains the benefits of pistol case gauges and shows how to use them. Gavin uses the quality gages produced by L.E. Wilson. These are available for the most popular handgun cartridges, both autoloader cartridges, and rimmed revolver cartridges. Gavin demonstrates gage use with .40 SW and .44 magnum cases.
Gavin states: “Using a case gage is very simple, and I would recommend that you add one of these gages to your reloader’s tool chest for each of the pistol cartridge types you reload. It may just save you a lot of time and hassle. Peace of mind is hard to put a price on!”
Creedmoor Sports is a leading vendor of products for competitive shooters and serious hand-loaders. Along with great gear, Creedmoor Sports provides informative content for its customers. The Creedmoor InfoZone provides Reloading Tips, Gear Reviews, Shooting News, and basic gunsmithing information.
Bill Gravatt, President of Creedmoor Sports, is an expert on reloading processes and gear. He developed many of the popular tools marketed by Sinclair Int’l, and he brings that expertise to Creedmoor Sports. Bill hosts a series of “how-to” videos produced for the Creedmoor InfoZone.
In this video, Bill Gravatt demonstrates several methods to clean your cases. Bill tells us: “Powder residue should be removed before you insert your cases into your reloading dies. There are several ways to clean your cases. Many shooters use a combination of various methods…”
1. Manual Cleaning — You can use 0000 Steel wool for the outside of the case and a Case Neck brush for the inside. A paper towel can remove any remaining residue. This is a handy way to clean if you load at the range.
2. Vibratory Tumbling — This traditional method works well, particularly for pistol brass. Experiment with both Corn Cob and Walnut media. You can get a brighter shine by putting a small amount of liquid brass polish in the media.
3. Wet Tumbling with Stainless Media — This process can get your brass clean inside and out. Do check to ensure no pins are stuck in the flash-holes. Watch for peening of case mouths that can occur over time.
4. Ultrasonic Cleaning — Ultrasonic cleaning works great for small parts as well as brass. The ultrasonic process removes all carbon and traces of lube, which can leave the inside of case necks too dry. To smooth bullet seating, try putting a tablespoon of Ballistol in the cleaning solution.
Cleaning Reloading Dies
Cleaning your reloading dies is something that many hand-loaders neglect. In this 60-second Tech Tip, Bill Gravatt provides some smart advice on cleaning your dies. Bill notes: “After heavy use, case lube and carbon can build up in your reloading dies. It’s important to keep them clean. Also, with new dies, give them a good cleaning before first use, because they ship with a corrosion inhibitor.”
1. Step 1 — Prior to cleaning, disassemble the die and spray it with a good degreaser. Do this with brand new dies too.
2. Step 2 – Take a patch and run it in the die to remove old lube and gunk. Don’t forget the decapping assembly and other internal parts.
3. Step 3 — After cleaning the die, but before reassembly, spray the die with a good corrosion inhibitor, such as Corrosion-X or Starrett M1.
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Here are two different bullet types, seated to the same CBTO length, but different COAL. Note the shiny scratches on the bullets made by the comparator tool which indicates a point on the bullet ogive near where the ogive will engage the rifling.
Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2 by Bryan Litz forBerger Bullets. Part One of this series focused on the importance of COAL in terms of SAAMI standards, magazine lengths, seating depths, and pressure levels. Another measure of length for loaded ammunition is highly important to precision, namely Cartridge Base to Bullet Ogive Length (CBTO).
Figure 2. Chamber throat geometry showing the bullet jump to the rifling or lands.
Look at Figure 2. Suppose the bullet was seated out of the case to the point where the base of the bullet’s nose (ogive) just contacted the beginning of the riflings (the lands) when the bolt was closed. This bullet seating configuration is referred to as touching the lands, or touching the riflings and is a very important measurement to understand for precision hand-loading. Due to the complex dynamics of internal ballistics which happen in the blink of an eye, the distance a bullet moves out of the case before it engages the riflings is highly critical to precision potential. Therefore, in order to systematically optimize the precision of his handloads, it’s critically important that the precision hand-loader understands how to alter bullet seating depth in relation to the barrel rifling. Part of the required knowledge is understanding how to accurately and repeatably measure the Cartridge Base To Ogive (CBTO) dimension. This is explained in the FULL ARTICLE.
Bryan Litz offers an extended discussion on how to measure CBTO using different tools and methods, including the Hornady OAL gauge. You can read this discussion in the full article found on the Berger Bullets website. CLICK HERE to Read Full Article.
Why Not Use CBTO as a SAAMI Standard?
If CBTO is so important to rifle accuracy, you might ask, “Why is it not listed as the SAAMI spec standard in addition to COAL?” There is one primary reason why it is not listed in the standard. This is the lack of uniformity in bullet nose shapes and measuring devices used to determine CBTO.
Benefits of Having a Uniform CBTO
There is another aspect to knowing your CBTO when checking your COAL as it pertains to performance. With good bullets, tooling, and carefully-prepared cases you can easily achieve a CBTO that varies less than +/- .001″ but your COAL can vary as much as .025″ extreme spread (or more with other brands). This is not necessarily bad and it is much better than the other way around. If you have a CBTO dimension that varies but your COAL dimension is tight (within +/- .002″) then it is most likely that your bullet is bottoming out inside the seater cone on the bullet tip. This is very bad and is to be avoided. It is normal for bullets to have precisely the same nose shape and it is also normal for these same bullets to have nose lengths that can vary as much as .025″.
Summary of Cartridge Base To Ogive (CBTO) Discussion
Here are four important considerations regarding bullet seating depth as it relates to CBTO:
1. CBTO is a critical measurement to understand for handloaders because it’s directly related to precision potential, and you control it by simply setting bullet seating depth.
2. Tools and methods for measuring CBTO vary. Most of the measurement techniques have pitfalls (which may give rise to inconsistent results) that you should understand before starting out.
3. A CBTO that produces the best precision in your rifle may not produce the best precision in someone else’s rifle. Even if you have the same rifle, same bullets, same model of comparator gauges, etc. It’s possible that the gauges are not actually the same, and measurements from one don’t translate to the same dimension for another.
4. Once you find the CBTO that produces the best precision in your rifle, it’s important to allow minimal variation in that dimension when producing quality handloads. This is achieved by using quality bullets, tooling, and properly preparing case mouths and necks for consistent seating.
The Tactical Rifle Shooters Facebook Group recently showcased tools used to measure case headspace before and after “bumping” the shoulder. After a case is fired, hand-loaders who full-length size their cases will typically bump the shoulders back anywhere from .001″ to .0035″, depending on the rifle and application. With our 6mmBR and Dasher cases we like about .0015″ bump.
You want the amount of case sizing and bump to be the same for all your brass. To ensure uniformity, it makes sense to measure your cases before and after the FL sizing process. When we have time, we check every case. Other folks will simply check the first 3-4 cases coming out of the FL sizing die to ensure the FL die setting is correct and delivering desired headspace/bump.
1. Whidden Gunworks Shoulder Bump Gauge
There are a variety of tools that can be used to measure shoulder bump. Our favorite is a special cartridge-specific bushing made by Whidden Gunworks. The Whidden Shoulder Bump Gauge enables you to adjust your sizing die to the desired measurement. The bump gauge is attached to your calipers with a set screw and determines the measurement from the base to the shoulder of the case. The photo below, from Tactical Rifle Shooters, shows the Whidden Bump Gauge for the .375 CheyTac cartridge.
2. Dave Manson Vertical Comparator with Dial Read-Out
Dave Manson states: “This tool was designed to make life easier for the advanced shooter and re-loader by allowing precise measurement of ammunition, case, and chamber headspace. With this information, the re-loader will be able to fine-tune clearances and fits between his ammunition and chamber, with resultant improvements in accuracy and case life.” The functions of the Manson Comparator are:
1. Measure headspace of factory or reloaded ammunition
2. Quantify chamber headspace by measuring headspace of a fired case
3. Ensure minimal shoulder set-back when setting up re-loading dies
4. Compare base-to-ogive length to ensure consistent bullet-to-rifling relationship.
Hornady’s Lock-N-Load Headspace Comparator system is easy-to-use and handy. You can get a kit with Red bushing-holder body and 5 bushings for $39.99 at Midsouth. Hornady explains: “The Lock-N-Load® Headspace Comparator… gauge measures variations in brass before and after firing or re-sizing. It allows for headspace comparison between fire-formed brass and re-sized brass.” IMPORTANT: Hornady states: “To determine the proper bushing diameter for your cartridge, simply add the neck diameter and the shoulder diameter and divide that number by two. Use the bushing closest to that number.” Hornady offers five: .330″, .350″, .375″, .400″, and .420″.
One tip — We have found the Hornady gauges may vary a little from unit to unit even with the same nominal size. If you have more than one gauge for the same cartridge, test each on your brass — you may then note a slight difference in your bump measurements. Mark one and use that consistently. There is also an Anvil Base Kit that mounts to the opposite blade on the caliper. This provides a more stable surface for the base of your case.
4. L.E. Wilson Case Gage Depth Micrometer
If you are looking for precise “bump” measurements without having to mess with calipers and clamp-on gauge blocks, you may want to consider the L.E. Wilson Case Gage Depth Micrometer (currently $130.00). This takes very precise, repeatable measurements, but you need to know your starting point. The manufacturer explains: “Every reloader should know exactly how much your Full Length Sizing Die is pushing back the shoulder. With the NEW Case Gage Depth Micrometer you can do just that! It has never been easier to measure you cases headspace before and after sizing. The Depth Mic allows you to slip the micrometer perfectly over the top of the Gage with your case inserted into the Gage and take a measurement. Micrometer has graduations of .001″. The Case Gage Depth Micrometer is set to a zero of .100″ on the scale at our factory. Because of differences in ‘feel’ and temperature, we include a the Gage Block for you to test Zero and to adjust if necessary.”
5. Pistol Brass Case DIY Bump Gauge
Last is a “field expedient” set-up if you do not have any of the comparator tools shown above. A sized .45 ACP case (or other suitable pistol case) can be used to measure shoulder bump. The mouth of the pistol case sits on the shoulder of your rifle cartridge brass.
Make sure the .45 ACP case is trimmed square and that it is round. We recommend you first run it through an expander, then size it, trim it and chamfer. Next, take the .45 ACP case and slip it over the neck of a fired, unsized rifle case with the primer removed. Align the two cases between the jaws of your calipers and note the length from rim to rim (See left photo below).
OK, now you have the length for a fired rifle case BEFORE sizing. Next, take a full-length sized rifle case (without primer) and do the same thing, placing the .45 ACP case over the neck of the FL-sized case (Right Photo). The difference between the two numbers is the amount of “bump” or set-back you are applying to the shoulder. Here the difference is .0015″. The amount of bump you need varies with your chamber and your load, but .0015-.002″ is a good initial setting.
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When neck-turning cases, it’s a good idea to extend the cut slightly below the neck-shoulder junction. This helps keep neck tension more uniform after repeated firings, by preventing a build-up of brass where the neck meets the shoulder. One of our Forum members, Craig from Ireland, a self-declared “neck-turning novice”, was having some problems turning brass for his 20 Tactical cases. He was correctly attempting to continue the cut slightly past the neck-shoulder junction, but he was concerned that brass was being removed too far down the shoulder.
The last half-inch or so of your barrel is absolutely critical. Any damage (or abnormal wear) near the crown will cause a significant drop-off in accuracy. Here are ways you can check the end of your barrel, using a common Q-Tip.
A while back, Sinclair International’s Reloading Press Blog featured a “round-table” discussion of reloading techniques. Sinclair’s team of tech staffers were asked: “What do you feel is the one-most crucial step in precision reloading?”
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2
