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.

Glen authored many excellent books on reloading. This article is adapted from two of Glen’s books: Handloading For Competition and Top-Grade Ammo.

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.

Many shooters prefer to deprime their brass before resizing. That way they can tumble cases or keep primer debris off their main press. To deprime cases before sizing or cleaning you can use a Decapping Die. This pushes out the spent primer without changing the neck or body of a case. Such decapping dies work fine, but they do require the use of a press. Here is a handy alternative — a cool tool that allows you to deprime brass anywhere — no press needed.

Handheld Primer Removal Tool From Frankford Arsenal
This cleverly-designed Hand Deprimer Tool allows you to deprime cartridge cases without a press. This hand-tool from Frankford Arsenal will deprime brass and capture primers conveniently. You can deprime your cases while watching TV or relaxing in your favorite chair.

This device lets you remove spent primers anywhere — no press needed and all the mess (cups/anvils/residue) stays in the capture chamber. This tool comes works with nearly all common case types up to .338 Lapua Magnum. With good leverage, this tool does the job quickly and efficiently. Forum members have praised this handy tool, but recommend wearing a thick glove if doing more than 100 cases in a session.

How to Adapt Tool for Small Flash Hole Brass
The Frankford Arsenal Deprimer Tool was designed for LARGE flash-hole brass. To deprime brass with small (1.5mm/0.59″) small flash-holes, as found on Lapua .220 Russian and 6mmBR cases, you will need to reduce the pin diameter. Frankford Arsenal currently recommends purchasing a replacement pin and “sanding it down” to the smaller diameter. NOTE: This is NOT difficult — simply spin the stock pin in some sandpaper.

This handy depriming tool is very versatile. With a universal, cylinder-style cartridge-holder, the tool can deprime a wide variety of cartridge types from .20 caliber up to .338 caliber. Three different plastic collets are provided to handle for different diameter cases. Spent primers are captured in a removable spent primer catch tube. Simply twist off the clear catch tube to dump the spent primers. With die-cast metal construction, this tool should last through many thousands of depriming cycles. MSRP is $65.99. Right now it is $47.99 on Amazon with 82% 5-star ratings.

Long-term User Review
One owner of this depriming tool has posted: “I have owned one of these for about eight years and deprimed over 10,000 cases with this tool. I have never had to replace a single part on it. You will have to adjust the return spring every so often, but that is a very easy task. If you are depriming a LOT of brass, the handle can tear up your hand a bit. Solution: Wear a Mechanics Glove. Easy Peasy! You will NOT regret this purchase.”

User Modifications — Grip Padding and High-Volume Capture
Many users recommended putting some kind of padding on the grip and front lever to reduce pressure on the fingers. This can be done with a wrap or a rubber covering. In addition, users have adapted the unit with an attached hose and large primer capture jug. If you depriming hundreds of cases at a time, this hose conversion may make sense.

Tumblers and walnut/corncob media are old school. These days many shooters prefer processing brass rapidly with an ultrasonic cleaning machine. When used with the proper solution, a good ultrasonic cleaning machine can quickly remove remove dust, carbon, oil, and powder residue from your cartridge brass. The ultrasonic process will clean the inside of the cases, and even the primer pockets. Tumbling works well too, but for really dirty brass, ultrasonic cleaning may be a wise choice.

READ FULL UltimateReloader.com Article on Ultrasonic Case Cleaning »

Our friend Gavin Gear has evaluated an RCBS Ultrasonic cleaning machine using RCBS Ultrasonic Case Cleaning Solution (RCBS #87058). To provide a real challenge, Gavin used some very dull and greasy milsurp brass: “I bought a huge lot of military once-fired 7.52x51mm brass (fired in a machine gun) that I’ve been slowly prepping for my DPMS LR-308B AR-10 style rifle. Some of this brass was fully prepped (sized/de-primed, trimmed, case mouths chamfered, primer pockets reamed) but it was gunked up with lube and looking dingy.”

UltimateReloader.com Case Cleaning Video (7.5 minutes):

Gavin describes the cleaning exercise step-by-step on UltimateReloader.com. Read Gavin’s Cartridge Cleaning Article to learn how he mixed the solution, activated the heater, and cycled the machine for 30 minutes. As you can see in the video above, the results were impressive. If you have never cleaned brass with ultrasound before, you should definitely watch Gavin’s 7.5-minute video — it provides many useful tips and shows the cleaning operation in progress from start to finish.

Ultra Dry Necks After Ultrasonic Cleaning — Some Suggestions
The Ultrasonic cleaning process gets cartridge brass so “squeaky clean” that increased force may be required to seat your bullets, or they may “grab” as they go in the necks. To reduce bullet-seating effort, you may benefit from adding a little dry case lube inside the case-neck before loading (use a nylon brush). Another trick is adding a teaspoon of Ballistol lube to the cleaning solution. That provides a trace lubricant inside the necks, but does not interfere with powder ignition in any way.

The latest Gen2 RCBS ultrasonic cleaning machine has a large 6.3-quart capacity. That’s nearly 100% larger than the first generation machine in Gavin’s video. The Gen2 machine, $434.52 on Amazon, features a second ceramic heater and transducer to better clean brass cases and firearm parts. The LED is easily programmable, and the timer can be set for up to 30 minutes of cleaning. The original 3.2 quart-capacity RCBS ultrasonic machine, as shown in Gavin’s video, is still available for $213.99 at Midsouth Shooters.

Before you load that new cartridge brass for the first time, run an expander mandrel down the case necks. This will iron out dents and provide more uniform neck tension. Chose a mandrel diameter that provides appropriate neck tension.

Lapua brass is so good that you’ll be tempted to just load and shoot, if you have a “no-turn” chamber. However, some minimal case prep will ensure more uniform neck tension. Keeping your neck tension very uniform allows more consistent bullet seating. That, in turn, usually yields better accuracy, and lower Extreme Spread and Standard Deviation (ES/SD). Lapua brass, particularly 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win comes from the factory with tighter-than-optimal necks.

Before you seat bullets, at a minimum, you should inside chamfer the case mouths, after running an expander mandrel down the necks. The expander mandrels from both Sinclair Int’l (Brownells, $14.99 stainless, $24.99 Titanium Nitride coated) and K&M will both leave the necks with enough neck tension (more than .001″) so you can then seat bullets without another operation. We suggest putting a bit of lube on the mandrel before running it down the necks — but remove any lube that gets inside the necks before seating bullets. If you do a lot of loading you may benefit from a Titanium Nitride-coated mandrel.

Both Sinclair and K&M Tools make a die body specifically to hold expander mandrels. The $49.99 Sinclair version fits caliber-specific expander mandrels which measure approximately .001″ less than bullet diameter for each caliber. This is an updated “Gen II” design that completely captures the mandrel within the die so the mandrel cannot pull out. It also has an O-ring in the die cap that allows the mandrel to self-center within the case neck. Brownells offers two sizes of Sinclair die bodies for expander mandrels: .17 -.338 caliber (#749011715 $49.99); and .357 – .50 caliber (#749008843, $49.99). All Generation II dies are machined from stainless steel and the standard diameter 7/8-14 dies include the Sinclair Stainless Steel Split Lock Ring.

Once you run the expander mandrel down the necks of Lapua brass, after you account for brass spring-back, you’ll have about .002″ neck tension*. This will make the process of seating bullets go much more smoothly, and you will also iron out any dents in the case mouths. Once the case mouths are all expanded, and uniformly round, then do your inside neck chamfering/deburring. The same expander mandrels can be used to “neck-up” smaller diameter brass, or prepare brass for neck-turning.

Forum member Mike Crawford adds: “These expanders can also reduce runout from offset seating. Prior to bullet seating, expand the sized necks to force thickness variance outward. With the Sinclair system, the necks will springback fine, and will not be pulled out of center. This leaves plenty of tension, and bullets seated more centered. I do this, even with turned necks, to get improved seating.”

Mandrels vs. Expander Balls on Decapping Rods
If you haven’t acquired an appropriate expander mandrel for your brass, but you DO have a full-length sizing die with an expander ball, this will also function to “iron out” the necks and reduce tension. However, using a die with an expander ball will work the necks more — since you first size them down, then the ball expands them up again. Typically (but not always), run-out is worse when using an expander ball vs. an expander mandrel.

* This .002″ tension is what we have observed with Lapua 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win brass. This might vary with much smaller or larger cases, and of course a different brand of brass might yield different results. If you get too little tension with your current mandrel, you can get a smaller-diameter mandrel from 21st Century Innovation, with stainless, Black Nitride, or Titanium nitride versions. The Nitride models have less friction.

Many shooters these days clean their cartridge brass ultrasonically, or wet-tumble their cases with stainless media (above). Both methods get brass clean and shiny, inside and out. However, when those wet-cleaning processes are completed, you’re left with a pile of soaking wet brass. How do you dry your brass quickly and efficiently, without unsightly water spots? Read on for some great answers…

In our Shooters’ Forum, Member Terry asked: “How do you dry your brass after Ultrasonic cleaning?” In a Reloading Forum Thread, many smart suggestions were posted. A dozen fellow members outlined a variety of effective case-drying procedures, which work equally well for both wet-tumbled brass and ultrasonically-cleaned cases. Here are the Top 10 brass-drying suggestions from our Forum members.

TOP TEN Ways to Dry Cartridge Brass After Wet Cleaning

1. Food Dehydrator — Shake the brass in towel to get the bulk of water off. Next leave in the food dehydrator for 45 minutes or until there are no signs of moisture inside the cases. — Lawrence97

2. Lyman 5-Level Case Dryer — Rinse off cleaning solution(s), then load brass by type into racks in Lyman Cyclone Case Dryer. This is easier to load/unload than food dehydrators and holds more cases.

3. Hot Water + Compressed Air — Rinse all your cases as a batch using scalding hot water from the kitchen sink. Hot water evaporates off of brass very very quickly. Then hit them with compressed air. Takes 10 minutes. Simple. — SG4247

4. Oven Dry in Pre-Heated Oven — After pre-heating to 200° or so, turn off oven and put brass inside on a tray. Most important! Tell your wife what you are doing so she doesn’t crank it up to 425 to heat pizza! — MClark

NOTE: Many other members suggested oven drying at 150-200°. We recommend turning OFF the oven so you don’t cook your brass if you forget to remove the cases.

5. Towel Dry then Warm with Heat Gun — Roll brass in a towel until no more water shakes out. Lay out on cardboard box top and blow off with Harbor Freight heat gun. $9.99 on coupon. Two minutes of heated air and about half hour of wait and they are good to go. This is with primers removed. — Shaggy357

6. Compressed Air, then Sun Dry Outside – I rinse the brass, then blow them out with compressed air. Then, dependent on the time of year, lay them on a towel in the sun. — HogPatrol

7. Dishwasher on Dry Cycle – In the winter, I drop my wet brass cases neck-down on the rack pegs in the dishwasher, then turn on the dry cycle. In the summer…well, I’m in Texas. They go to the porch for a bit. — Toolbreaker

8. Alcohol Rinse then Air or Oven Dry — Rinse in 90% Isopropyl alcohol and either let air dry or stick in 175° oven for half an hour. Alternatively, use a dehydrator. — Zipollini

9. Slow Air-Dry in Loading Blocks — I have a reloading block with holes drilled in it. I simply load the block up and let it air-dry in the cupboard for a couple of days. — JCS

10. Wipe with Towel Then Anneal Normally — This thread is stirring my OCD side. Seems complicated for just drying — my brass dries just fine when I anneal it. This entire process can’t take an hour per batch. When finished, the brass is cleaned, annealed, and ready to size. — CHLuke

• Deprime, then tumble brass with stainless media, water, Lemishine, and dish detergent.
• Shake them easily in a strainer to knock out most media then grab 4-5 pieces, shake them over the bucket for the last of the media then inside a towel.
• Finally blow out the primer pockets and wipe with a towel, load in the Annealeez.

Tumblers and walnut/corncob media are old school. These days many shooters prefer processing brass rapidly with an ultrasonic cleaning machine. When used with the proper solution, a good ultrasonic cleaning machine can quickly remove remove dust, carbon, oil, and powder residue from your cartridge brass. The ultrasonic process will clean the inside of the cases, and even the primer pockets. Tumbling works well too, but for really dirty brass, ultrasonic cleaning may be a wise choice.

READ FULL UltimateReloader.com Article on Ultrasonic Case Cleaning »

Our friend Gavin Gear has evaluated an RCBS Ultrasonic cleaning machine using RCBS Ultrasonic Case Cleaning Solution (RCBS #87058). To provide a real challenge, Gavin used some very dull and greasy milsurp brass: “I bought a huge lot of military once-fired 7.52x51mm brass (fired in a machine gun) that I’ve been slowly prepping for my DPMS LR-308B AR-10 style rifle. Some of this brass was fully prepped (sized/de-primed, trimmed, case mouths chamfered, primer pockets reamed) but it was gunked up with lube and looking dingy.”

UltimateReloader.com Case Cleaning Video (7.5 minutes):

Gavin describes the cleaning exercise step-by-step on UltimateReloader.com. Read Gavin’s Cartridge Cleaning Article to learn how he mixed the solution, activated the heater, and cycled the machine for 30 minutes. As you can see in the video above, the results were impressive. If you have never cleaned brass with ultrasound before, you should definitely watch Gavin’s 7.5-minute video — it provides many useful tips and shows the cleaning operation in progress from start to finish.

Ultra Dry Necks After Ultrasonic Cleaning — Some Suggestions
The Ultrasonic cleaning process gets cartridge brass so “squeaky clean” that increased force may be required to seat your bullets, or they may “grab” as they go in the necks. To reduce bullet-seating effort, you may benefit from adding a little dry case lube inside the case-neck before loading (use a nylon brush). Another trick is adding a teaspoon of Ballistol lube to the cleaning solution. That provides a trace lubricant inside the necks, but does not interfere with powder ignition in any way.

The latest Gen2 RCBS ultrasonic cleaning machine has a large 6.3-quart capacity. That’s nearly 100% larger than the first generation machine in Gavin’s video. The bigger Gen2 machine, $419.99 at Precision Reloading (with FREE shipping), features a second ceramic heater and transducer to better clean brass cases and firearm parts. The LED is easily programmable, and the timer can be set for up to 30 minutes of cleaning. The original 3.2 quart-capacity RCBS ultrasonic machine, as shown in Gavin’s video, is still available for $197.99 at Midsouth Shooters. There is also another good 6-liter multi-mode ultrasonic cleaning machine, with stainless steel tank, available for $199.99 on Amazon.

We are re-publishing this article at the request of Forum members who found the information very valuable. If you haven’t read this Safety Tip before, take a moment to learn how you can inspect your fired brass to determine if there may be a potential for case separation. A case separation can be dangerous, potentially causing serious injury.

On the highly-respected Riflemans’ Journal blog, created by our late, dear friend German Salazar*, there was an excellent article about Cartridge Case-Head Separation. In this important article, Salazar (aka GS Arizona) examined the causes of this serious problem and explained the ways you can inspect your brass to minimize the risk of a case-head separation. As cases get fired multiple times and then resized during reloading, the cases can stretch. Typically, there is a point in the lower section of the case where the case-walls thin out. This is your “danger zone” and you need to watch for tell-tale signs of weakening.

The photo below shows a case sectioned so that you can see where the case wall becomes thinner near the web. You can see a little arrow into the soot inside the case pointing to the thinned area. This case hadn’t split yet, but it most likely would do so after one or two more firings.

Paper Clip Hack for Detecting Problems
The article provided a great, easy tip for detecting potential problems. 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. If you do this every time you reload, on at least 15% of your cases, you’ll develop a good feel for what the thin spot feels like and how it gets worse as the case is reloaded more times. And if you’re loading the night before a match and feel pressured for time — don’t skip this step!”

Before you load that new cartridge brass for the first time, run an expander mandrel down the case necks. This will iron out dents and provide more uniform neck tension. Chose a mandrel diameter that provides appropriate neck tension.

Lapua brass is so good that you’ll be tempted to just load and shoot, if you have a “no-turn” chamber. However, some minimal case prep will ensure more uniform neck tension. Keeping your neck tension very uniform allows more consistent bullet seating. That, in turn, usually yields better accuracy, and lower Extreme Spread and Standard Deviation (ES/SD). Lapua brass, particularly 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win comes from the factory with tighter-than-optimal necks.

Before you seat bullets, at a minimum, you should inside chamfer the case mouths, after running an expander mandrel down the necks. The expander mandrels from both Sinclair Int’l (Brownells, $14.99 stainless, $24.99 Titanium Nitride coated) and K&M will both leave the necks with enough neck tension (more than .001″) so you can then seat bullets without another operation. We suggest putting a bit of lube on the mandrel before running it down the necks — but remove any lube that gets inside the necks before seating bullets. If you do a lot of loading you may benefit from a Titanium Nitride-coated mandrel.

Both Sinclair and K&M Tools make a die body specifically to hold expander mandrels. The $49.99 Sinclair version fits caliber-specific expander mandrels which measure approximately .001″ less than bullet diameter for each caliber. This is an updated “Gen II” design that completely captures the mandrel within the die so the mandrel cannot pull out. It also has an O-ring in the die cap that allows the mandrel to self-center within the case neck. Brownells offers two sizes of Sinclair die bodies for expander mandrels: .17 -.338 caliber (#749011715 $49.99); and .357 – .50 caliber (#749008843, $49.99). All Generation II dies are machined from stainless steel and the standard diameter 7/8-14 dies include the Sinclair Stainless Steel Split Lock Ring.

Once you run the expander mandrel down the necks of Lapua brass, after you account for brass spring-back, you’ll have about .002″ neck tension*. This will make the process of seating bullets go much more smoothly, and you will also iron out any dents in the case mouths. Once the case mouths are all expanded, and uniformly round, then do your inside neck chamfering/deburring. The same expander mandrels can be used to “neck-up” smaller diameter brass, or prepare brass for neck-turning.

Forum member Mike Crawford adds: “These expanders can also reduce runout from offset seating. Prior to bullet seating, expand the sized necks to force thickness variance outward. With the Sinclair system, the necks will springback fine, and will not be pulled out of center. This leaves plenty of tension, and bullets seated more centered. I do this, even with turned necks, to get improved seating.”

Mandrels vs. Expander Balls on Decapping Rods
If you haven’t acquired an appropriate expander mandrel for your brass, but you DO have a full-length sizing die with an expander ball, this will also function to “iron out” the necks and reduce tension. However, using a die with an expander ball will work the necks more — since you first size them down, then the ball expands them up again. Typically (but not always), run-out is worse when using an expander ball vs. an expander mandrel.

* This .002″ tension is what we have observed with Lapua 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win brass. This might vary with much smaller or larger cases, and of course a different brand of brass might yield different results. If you get too little tension with your current mandrel, you can get a smaller-diameter mandrel from 21st Century Innovation, with stainless, Black Nitride, or Titanium nitride versions. The Nitride models have less friction.

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.

Glen authored many excellent books on reloading. This article is adapted from two of Glen’s books: Handloading For Competition and Top-Grade Ammo.

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.