Ever wondered what caused a particular bulge or marking on a case? And more importantly, does the issue make the case unsafe for further use? Sierra Bullets Ballistic Technician Duane Siercks offers some insight into various issues and their causes in two Case Diagnostic articles from the Sierra Blog.
Incipient Case-Head Separation
This is a Winchester .308 Win case that has a real issue. This case has a very obvious incipient case head separation in the process of becoming a complete failure.
This is most commonly caused by over-sizing the case causing there to be excess headspace on the case. After a few firings and subsequent re-sizing, this case is just about ready to come completely apart. Proper die adjustment is certainly a requirement here. Of course this case is not safe to reuse.
Excessive Pressure (Load Too Hot)
If you will notice in the picture of the case rim, there are two pressure signs to notice. First, look at the primer. It is basically flattened to about the max of what could be considered safe. If this was the only pressure sign noted, I would probably be fine with this load, but would constantly keep an eye on it especially if I was going to use this load in warmer temperatures. This load could easily cross into the “excess pressure” realm very quickly.
There is another sign of pressure that we cannot ignore. If you’ll notice, there is an ejector mark apparent that is located over the “R” of the R-P headstamp. This absolutely tells us that this load would not have been in the safe pressure range. If there were any of these rounds loaded, they should not be fired and should be dis-assembled. This case should not be reloaded.
Split Case-Neck
Here we have an R-P .22-250 case that has died the death. Everything looks fine with this case except the neck is split. This case must be tossed.
A split neck is a normal occurrence that you must watch for. It is caused by work-hardening of the brass. Brass cases get harder with age and use. Brand new cases that are stored for a period of time can become hard enough that they will split like this case within one to two firings. I have had new factory loads do the same thing. Then as we resize and fire these cases repeatedly, they tend to get harder and harder. Eventually they will split. The life of the case can be extended by careful annealing practices. This is an issue that would need to be addressed in an article by itself. Of course this case is no longer usable.
In the classes that I teach, I try to use examples like this to let the students see what they should be looking for. As always, if we can assist you, whether you are new to reloading or very experienced, contact us here at Sierra Bullets by phone at 1-800-223-8799 or by email at sierra@sierrabullets.com.
Dented Case Body
Here we have a Lake City 7.62×51 (.308 Win.) case with two heavy marks/dents in the case body.
This one may be a bit of a mystery. It appears as if this case may have been caught in the action of a semi-auto rifle when the firearm jammed or the case failed to clear during the cycling process. I probably would not reload this case just to prevent any feeding problems. This also appeared to be a factory loaded round and I don’t really see any pressure issues or damage to the case.
Multiple Problems — Lake City 5.56×45 unknown year.
This case has suffered multiple failures and cannot be re-used. First its has have a very rounded shoulder that is split. Upon first look it was obvious that this round had been a victim of excess pressure. The firearm (perhaps an AR?) was apparently not in full battery, or there was possibly a headspace issue also. While taking a closer look, the primer was very flat and the outside radius of the primer cup had been lost. High pressure! Then I also noticed that there was an ejector mark on the case rim. This is most certainly an incident of excessive pressure. This case is ruined and should be discarded.
It is very important to observe and inspect your cases before each reloading. After awhile it becomes second nature to notice the little things. Never get complacent as you become more familiar with the reloading process. If ever in doubt, call Sierra’s Techs at 1-800-223-8799.
At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
NOTE: All listed products are for sale to persons 18 years of age or older. No products are intended for use by minors.
MidwayUSA — RCBS Reloading Tools Sale
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If you need a press, reloading scale, dies, or other loading tools, definitely check out the major RCBS Sale running now at MidwayUSA. They have everything RCBS on sale, including Presses, Combo Reloading Kits, ChargeMaster Electronic Scale/Dispensers, Priming tools, Mechanical scales, Dies and more — all priced to move. There are very significant savings, up to 25%. For example the innovative RCBS Summit Press is $75 off, a 20% savings while a RockChucker combo reloading kit is $125 off, also 20% discount.
Brownells — Labor Day Sale + 12% OFF with Code LABORDAY12
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Get big savings with the Brownells Labor Day Sale. Along with the already discounted prices, on select clearance items you can save an additional 12% by using Code LABORDAY12 during check-out. Sale items include rifle scopes, Howa barreled actions, Reloading equipment, Hunting packs, Ammo (rifle, pistol, shotgun), powder and primers. Definitely check out this Clearance Sale. There are exceptional deals plus there are ZERO HazMat Fees on Powder and/or Primer purchases with no minimum!
Natchez — Giant Ammo Sale
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If you need quality rimfire or centerfire ammo at great prices check out the Giant Ammo Sale at Natchez. There is regular and subsonic .22 LR rimfire ammo. For pistols, choose .380 ACP, 9mm Luger, or .45 ACP from CCI, Federal, and Remington. And there is Federal American Eagle 5.56 NATO (.223 Rem) rifle ammo. All these ammo types are heavily discounted. For example the 1000ct CCI Blazer 9mm ammo is $269.99, $50 off the regular $319.99 price. And along with the savings on the ammo, Natchez is offering $5 Flat Rate Shipping on $99+ Orders (use Code FR260903).
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When shooting groups at long range on paper it can be difficult to distinguish which bullet holes belong to a particular sequence of shots. If, for example, you shot three 5-shot groups at 600+ yards on a paper target, you would have 15 bullet holes on the target (assuming no misses). But at that distance it would be difficult to see the holes on target (even with a spotting scope). Accordingly, when you inspected the target up close, it would be hard to tell which shots belonged to which group. You might have a vague idea, but couldn’t be sure, without a target camera recording the shot sequence.
Here is a method to separate multiple shots into specific groups so you can better evaluate your load and shooting skills. The trick is pretty simple — mark your bullets with a color from a Sharpie or other felt marking pen. If you are shooting three 5-shot groups, mark five with red, five with green, and five with blue (or purple). Then, when you inspect the target, you can identify the group placements by the colors that appear on the paper.
Round Robin: Using colors you can shoot “Round-Robin” to evaluate seating depths, neck tension, or other variables without having the shot order (and barrel heating) affect group sizes unequally. For example you might have three different neck tensions, each marked with a different color on the bullets. Then shoot Red, Blue, Green in that sequence for five total shots per color.
Smart Tip to Show Colors More Vividly
If the bullet inks are not showing up on your target paper clearly, here is a simple trick that can make the colors “bleed” to be more visible. In your range kit, bring some alcohol solution along with some Q-tips. Then dab the shots on the paper target lightly with wet Q-Tips. Here is the front of a target before and after application of alcohol:
Forum Member NewbieShooter explains: “Dabbing a bit of alcohol on the bullet holes with Q-Tips makes the color pop a bit… especially on the back side.” See below:
In short order you will see the colors spread into the paper, clearly marking the shot holes by distinguishing colors. If you were shooting a dark bullseye, view the the BACK side of the target to see the colors on a light background.
Credits: Bullet Tips photo by Forum Member Dave Way; Target photos by Forum Member NewbieShooter; Story tip from Boyd Allen.
When shooting targets, the closer to the center the better the result. But this is not necessarily true when it comes to using jags and patches. There are some good reasons to try spiking your patches away from the center. This Creedmoor Sports Tech Tip explains why you may want to spike (puncture) your patch away from the center. CLICK HERE to order patches and Swab-Its cleaning bore tips from Creedmoor Sports.
You begin to push your first patch down the barrel and you notice it is extremely tight and then it jams! How can this be? A commonly overlooked solution to remedy the frustrating occurrences of overly tight or jammed patches is what we like to call “Side-Spiking”. Side-Spiking is super simple and works!
“Side-Spiking”, as the words suggest, refers to moving your patch spiking position from the center of the patch towards the corner of a square patch or the edge of a round patch.
Moving From Center-Spiking To Side-Spiking
The closer toward the edge of the patch you spike your jag, the looser the patch will be when pushed down the bore.
Important: Be careful to not go to the very edge of the patch. Leave enough patch material to fully cover the first set of rings on your jag as this insures your jag is properly centered in the bore and that no contact with the rifling will occur.
Proper Side-Spiking Location Creedmoor Sports recommends side spiking all wet patches. This allows for a looser patch in the bore which removes gross powder fouling and leaves more cleaning solution behind to start working on the remaining fouling.
When a tighter patch is needed, simply move your spike closer toward the center of the patch. The closer to the center of the patch you get, the tighter the patch will become in the bore. The objective is to have a snug-fitting patch that allows you to smoothly push your rod down the bore. Remember you do not need to end up in the center of the patch!
Bore-Tech Patch Size Selection Chart Recommends Patch Sizes by Caliber:
Shown are funnel with ultra-long drop tube (which helps get more kernels in the cases), RCBS Chargemaster (in wood box), and Hood Press (similar to Harrell’s Combo press).
Loading at the range remains important in the Benchrest for Group discipline. In a Special Report below, past IBS President Jeff Stover explains how loading methods (and hardware) have evolved over the years. The advent of accurate, affordable electronic powder dispensers, such as the RCBS ChargeMaster and Frankford’s new Intellidropper, have changed the game and made it easier to load efficiently at the range. And quality manual powder measures are fast and can be very consistent, with a little practice. Loading at the range permits competitors to tune their load to the conditions, change seating depths, or even choose different bullets to suit the barrel’s preferences on any given day.
Although pre-loading is not uncommon, most 100/200-yard group shooters usually load at the match, often between relays. The goal is to shoot smaller groups by staying “in tune”. In a game where 5-shot groups “in the 1s and Zeros” is the goal, tuning loads for the conditions helps deliver match-winning accuracy. Nearly all competitors in this short-range discipline shoot the 6mm PPC cartridge, or a PPC variant.
Loading at the Range — Then and Now
In benchrest shooting for group, loading at the range has been de rigueur for decades. In the Score discipline, preloading is usually the custom. The main reason is that, in Score competition, only one Aggregate (warm-up match and five record targets) per day is usually shot. That would be less than 50 shots, assuming a few sighter shots. Also, the 30BR, the dominant Benchrest-for-Score cartridge, is very amenable to pre-loading.
By contrast, the Group discipline includes 21 targets (two warm-ups and twenty record targets) over a weekend, usually shot with 6PPC-chambered rifles. Many times, the 6PPC shooters may tweak their loads through the day given changing atmospheric conditions or simply trying to find the correct tune to “dot up”. This term, “Dot up”, means the shots are essentially going through the same hole, or closely so.
Loading at the range was a bit different when benchrest competition was in its infancy. The 1951 book, Modern Accuracy by Bob Wallack, is the best of the early benchrest books. Copies can be found, from time to time, on eBay or Alibris. It is a fascinating survey of benchrest as it existed more than six decades ago. There’s even coverage of a controversial target that was argued over at the time. In it, there is a photo of Wallack using the rear bumper of a car at the bench to clamp his reloading tools. Things have come a long way compared to the range loading set-ups of modern shooters. Here you can see Bob Wallack way back in 1950:
Modern loading bench set-ups shown in this Special Report belong to top shooters Howie Levy, Bob Hamister, and Kent Harshman.
Here’s something you don’t see every day — the inside of loaded cartridges, sliced halfway through. This lets you see how bullet core, jacket, cartridge case, powder, and primer all fit together. Give credit to the folks at FOG Ammunition for creating this interesting series of cut-through ammo images. We show four cartridges here: the .308 Winchester, 9mm Luger, 300 BLK, and .50 BMG. You’ll find two more (the .223 Remington and .45 ACP) on the original FOG Ammo Blog Article.
This .308 Winchester model took on a different approach by only cutting the brass case and displaying the full bullet, primer and powder load. A spec amount of powder was used to create the model powder form. An estimated 10% volume was added during the forming process, along with an undetermined amount of air pockets.
This bisection is a 9mm Luger Jacketed Hollow Point round with flake powder held together with super glue. After this self-defense round was cut by a trained professional the round was polished by hand. This might look like stick powder, but those are in fact flakes stacked up in cross-section. Designed in 1901 by Georg Luger, this popular cartridge is used by civilians, military, and law enforcement.
For this model of the .300 AAC Blackout (aka 300 BLK), a Dremel tool was used to create a pie cut within the bullet and brass case. A measured amount of power, roughly 65% of spec charge, was placed inside the case with super glue. This cartridge was originally optimized for subsonic use with a suppressor, so the amount of powder used is small relative to the nominal case capacity. That leaves more room for the relatively large .30-caliber bullet.
Last but definitely not least is the .50 Caliber BMG round (aka .50 Browning Machine Gun). Famed for its wartime use in the M2 Machine gun, the .50 BMG round is also used in civilian Long Range competitions. A typical .50 BMG cartridge holds over 225 grains of powder. That’s almost ten times the amount in a 5.56×45 NATO Round! To demonstrate the size of the .50 BMG, check out that .223 Rem for comparison.
Close-up view of a sectioned case. This one here was “fixin’ to pop”, observed Glen Zediker.
Here are highlights from an article Glen Zediker wrote for the Midsouth Blog. In that article Glen, who sadly passed away in 2020, focused on cartridge brass. Glen identified the most common failures that appear with brass that has been shot multiple times, or which has been fired at excessive pressures. Glen explained some simple ways to check your cartridge brass to detect “early warning signs” of case failure, particularly case head separation, which can be very dangerous.
How Cases Degrade with Multiple Firings By Glen Zediker
This article explains when, and then how, to check after the progress of changes commencing with the firing on a new case. It’s the “progress of degeneration,” in a way of looking at it because the concern is getting a handle on when enough change in the brass has come about to require attention. Or abandonment. As said then, for me that’s 4 firings. That, as said last time, is when I might see changes that need attention. Also as said, that figure didn’t come out of a hat, but from my own notes in running my competition NRA High Power Rifle loads. [Editor’s Note: With Lapua brass, using moderate loads, in bolt-action rifles, we typically get about 10 good (match-worthy) firings. But if you anneal your Lapua brass, and run modest pressures, Lapua brass can perform well for 20 or more load cycles.]
The areas most affected are the case neck and case head area. Case neck walls get thicker [but] the case head area body walls get thinner. Primer pockets get shallower and larger diameter.
This case shows a cracked neck AND a crack (separation) above the case head. Zediker says it is “rare to see one case with both of the most common failures. [This case] was attacked by an M14.”
Case Head — Causes of Separation and Cracking
When a case is under pressure during firing, the brass, like water, flows where it can, where it’s more free to move. Of course, the chamber steel limits the amount it can expand. The case shoulder blows fully forward and the case base is slammed back against the bolt face. There is, therefore and in effect, a tug on both ends — it gets stretched. The shoulder area is relatively free to expand to conform to the chamber, but the other end, the case head area, is not. Since that’s the area of the case with the thickest walls, it doesn’t expand “out” much at all. What it does is stretch. The “case head area,” as I refer to it here, is the portion of the case above the web, which is just above the taper that leads in to the extractor groove. The “area” extends approximately an eighth-inch up the case body.
Here’s a “pressure ring.” You’ll see this after firing, if you see it. And, if you see it, that case is done. The bright ring indicates excessive stretching, which indicates excessive thinning. If you see a ring circling the case, noticeable because it’s lighter color than the case body, and it’s in this area, I’d say that case is done. And that’s right where a “head separation” occurs. It can crack and also blow slap in two, and that’s the “separation” part of case head separation.
Photo courtesy GS Arizona.
This is a spot to keep close watch on as cases age. It is also the area that is more “protected” by sizing with less case shoulder set-back. That is, pretty much, where the freedom for the stretching movement in this area comes from (the case shoulder creates a gap). If you’re seeing a sign that a head separation [might happen with relatively few firings], chances are the shoulder set-back is excessive, and also… the load pressure level.
Bent Paper Clip Case-Wall Gauge
Editor: You can use a bent paper clip to detect potential case wall problems. Slide the paper clip inside your case to check for thin spots. GS Arizona explains: “This simple little tool (bent paper clip) will let you check the inside of cases before you reload them. The thin spot will be immediately apparent as you run the clip up the inside of the case. If you’re seeing a shiny line on the outside and the clip is really hitting a thin spot inside, it’s time to retire the case.” Photo by GS Arizona.
Monitor Primer Pocket Dimensional Changes
Another case-head-area and pressure-related check is the primer pocket. As said, the primer pocket will get larger in diameter and shallower in depth each firing. As with many such things, the questions are “when” and “how much,” and the main thing, “how much?”
If the pocket gets excessively shallow, and that’s judged by a primer that seats fully but isn’t at least a tick below flush with the case base, there could be function issues. There’s a risk of a “slam-fire” with a semi-auto that uses a floating firing pin, and, if there is actual protrusion, that has the same effect as insufficient headspace. A primer pocket uniformer can reset the depth of a shallowed primer pocket to what it should be, but the real test for me is how easily the next primer seats into it. If it’s significantly less resistance, I’ll say that case is done. Shallower can be refurbished. That’s a primary function of a primer pocket uniformer. Larger diameter, though, can’t be fixed. I’ve mentioned in another article or two that, any more at least, my main gauge of load pressure has become how much primer pocket expansion there’s been.
Guys — honestly, if you do anything today on this site, watch this video. You won’t be disappointed. Guaranteed. This is a very informative (and surprisingly entertaining) video. Every serious hand-loader should watch this video to see how cartridge cases are made. Your Editor has watched the video 5 times now and I still find it fascinating. The camera work and editing are excellent — there are many close-ups revealing key processes such as annealing and head-stamping.
VERY Informative Video Show Cartridge Brass and Ammunition Production:
Norma has released a fascinating video showing how bullet, brass, and ammunition are produced at the Norma Precision AB factory which first opened in 1902. You can see how cartridges are made starting with brass disks, then formed into shape through a series of processes, including “hitting [the cup] with a 30-ton hammer”. After annealing (shown at 0:08″), samples from every batch of brass are analyzed (at multiple points along the case length) to check metal grain structure and hardness. Before packing, each case is visually inspected by a human being (3:27″ time-mark).
The video also shows how bullets are made from jackets and lead cores. Finally, you can watch the loading machines that fill cases with powder, seat the bullets, and then transport the loaded rounds to the packing system. In his enthusiasm, the reporter/narrator does sometimes confuse the term “bullets” and “rounds” (5:00″), but you can figure out what he means. We definitely recommend watching this video. It’s fascinating to see 110-year-old sorting devices on the assembly line right next to state-of-the art, digitally-controlled production machinery.
Video tip by EdLongrange. We welcome reader submissions.
Here’s an inexpensive product that can make your case prep and loading tasks easier. We use and recommend the cleverly-designed Lyman Bleacher Blocks. These multi-level (stepped) cartridge holders save space on your bench AND make it easier to select a particular case/cartridge from a full block. Each row is a different height for convenience. With Bleacher Blocks it’s also easier to check for powder levels, or place bullets before the seating process.
Lyman’s Bleacher Block cartridge holders have many advantages over conventional, single-level blocks. Use the different levels for sorting brass. Or, migrate the brass from top to bottom as you proceed through case prep stages. If you are assembling loads with different bullets for load testing, you could arrange the loaded rounds on different levels for easy recognition. For example put V-Max loaded rounds on the top tier, and Berger Hybrid loaded rounds on the bottom tier. Or, if you are experimenting with neck tension, you can use different rows for cases processed with different bushings.
Made of durable orange polymer, Lyman Bleacher Blocks are now molded in five sizes — small pistol, large pistol, and three rifle sizes. The smallest rifle block (with 0.388″-diam holes) fits .223 Rem-size case heads. The middle size rifle block (with 0.485″-diam holes) fits .308 Win-size case heads. That works for 6mmBR/Dasher sized cases perfectly. The biggest rifle Bleacher Block has 0.565″-diameter recesses for magnum-size cases. There are also two pistol blocks — .445″ hole size for 9mm/.357 size and .565″ diameter for larger .44/.45 pistol cartridges.
Here’s what Lyman says about its innovative cartridge block design: “Our [stepped] loading blocks allow for easier handling of cases in and out of the loading block. Our stepped design allows you to easily grip a single case without jamming your fingers down into a group of cases like in traditional loading blocks, and allows for a smaller ‘footprint’ on your bench.”
Lyman Bleacher Blocks are among the Reloading Tools reviewed in this helpful video:
Wouldn’t it be nice to have a print resource at your fingertips that has hundreds of true-size cartridge illustrations, plus technical descriptions of thousands of popular cartridge types? That could be a real time-saver. It’s no wonder this book is an Amazon category best-seller.
If you’re a serious shooter, the latest 7th Edition of the Ammo Encyclopedia belongs in your library. Released in late 2022, this 928-page book is probably the most comprehensive and up-to-date book in print covering current and obsolete cartridge and shotshell types. The Ammo Encyclopedia is a massive resource work with 100+ chapters, covering thousands of handgun, rifle, and shotgun cartridges from the past century and a half. This 928-page edition includes over 150 new cartridge profiles. An expanded Trademark Index lists contact information for all current ammunition manufacturers.
One of the best features is a full-color section with actual size drawings of over 320 current rimfire/centerfire cartridges and shotshells. You won’t find that many “life-size” cartridge drawings in one place even on the internet. Cartridge profiles and ballistic charts have been expanded to include many new factory cartridges. An updated Cartridge Index lists both the standard and alternate names for each cartridge in chronological order. The authors have even included air rifle pellets and historical images and charts. This 928-page softcover book is now just $29.99 on Amazon, 40% off list price.
Comments from guys who bought the book:
“This book contains a vast array of information on many modern and even obsolete ammunition. Definitely recommend for any modern reloader novice or experienced.” – Duggaboy460
“It’s a great reference book for individuals who reload their own ammunition. There is a lot more info in this Edition. Everyone who likes this information should have it in their library.” – Reloader
“Very comprehensive with great photos and detailed information. A Must have for anybody with several guns/ammo.” – M.Ibarra