We know that many of our readers are now tumbling their brass in liquid media rather than dry media such as corn-cob or walnut shells. When done with STM stainless tumbling media (small ss pins), this system really does work, producing brass that is clean “inside and out”. The only down-side to wet tumbling is that sometimes the inside of the caseneck gets so “squeaky clean” that bullets take more effort to seat. This can be remedied with the use of a dry lube inside the necks. When cleaning with stainless tumbling media you’ll need a quality tumbler that is water-tight. The wet-tumbler of choice is the Model B Thumler’s Tumbler. Featuring a bright-red, side-loading drum, the Model B Thumler’s Tumbler is reliable and built to last.
A while back, Bill Gravatt, then President of Sinclair Int’l, had a chance to evaluate the Thumler’s Tumbler and the wet-cleaning process for cartridge brass. Bill came away a believer: “I wanted to share with you my experience using the Thumler’s Tumbler and stainless steel pin media to clean brass.
What’s the next best thing to a stockpile of gleaming, freshly-loaded ammo? How about a movie showing gleaming, freshly-loaded ammo being made — from start to finish? The five-minute video below shows the ammunition production process at the Lake City Army Ammunition Plant, a division of ATK. Lake City is the largest producer of small arms ammunition for the U.S. military, producing roughly four MILLION small-caliber rounds every day.
This promotional video does go a bit overboard at times in a self-congratulatory sense. But the video is definitely worth watching — it is fascinating to watch the process of creating cartridges — from the drawing (or extrusion) of raw brass into casings to the placement of projectiles and primers.
Quick History of Lake City Ammunition Plant Lake City Army Ammunition Plant (LCAAP) is a 3,935-acre government-owned, contractor-operated facility in Independence, Missouri that was established by Remington Arms in 1941 to manufacture and test small caliber ammunition for the U.S. Army. The facility has remained in continuous operation except for one 5-year period following World War II. As of July 2007, the plant produced nearly 1.4 billion rounds of ammunition per year. Remington Arms operated the plant from its inception until 1985, when operations were taken over by Olin Corporation. From April 2001 through the present, it has been operated by Alliant Techsystems (ATK), which in February 2015 split into two separate companies, Orbital ATK and Vista Outdoors.
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Here’s something you don’t see every day — pistol-caliber Lapua brass. We shoot superior Lapua brass in our rifles, and now you can get the “good stuff” for your 9mm pistols too. It’s nice to know that Lapua 9mm brass is available for those guys who accept “nothing but the best”. Grafs.com received a special order of 9mm Luger (aka 9x19mm or 9mm NATO) pistol brass made by Lapua. It is available right now for $19.99 per 100-count bag or $179.99 per 1000-count box. That’s 38% off the regular 1K box price.
When It Pays to Shoot Premium Pistol Brass
Is this Lapua 9mm brass worth the price compared to the cheaper alternatives (such as once-fired police range pickups)? We think the answer depends on your application. If you shoot a 9mm pistol in Bullseye competition, yes it makes sense to get the Lapua. Or, if you have a 9mm revolver that carries the shells in a moon clip, the Lapua brass may be worth getting. With a 9mm revolver, your brass is not marred by an extractor claw and then ejected on to the ground. If we had the impressive new 8-shot, Miculek Edition Smith & Wesson model 929 9mm revolver (below), we’d definitely shoot Lapua brass.
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Forum member Erik Cortina recently launched his own YouTube Channel dedicated to precision reloading and accurizing. Erik’s videos demonstrate the proper use of specialized reloading tools and provide helpful hints. Erik’s latest video is about the “mother of all brass trimmers”, the Giraud powered case trimmer. Erik says: “It you do volume reloading… this is the only trimmer to get. It not only trims to length but it also chamfers your case mouth inside and out.” In his video, Erik offers some very clever and useful tips that will help you get the most from your Giraud.
The Giraud trimmer is very precise. When set up correctly, it can trim brass with amazing consistency. In the video, Erik trims 5 pieces of brass in 15 seconds (6:32 mark). He then measures all five with precision calipers (7:00-8:08). All lengths are exact within .0005 (half a thousandth). Erik notes that the Giraud trimmer indexes off the case shoulder. As long as you have fire-formed brass with consistent base-to-shoulder dimensions, you should get very consistent trim lengths.
The secret to the system is a 3-way cutting head. This cutter can be swapped in and out in a couple minutes with wrenches provided with the kit. Erik has three different heads; one each for 6.5mm, 7mm, and .30 caliber. The video shows how to adjust the cutting heads to match caliber diameter (and to get the desired amount of inside/outside chamfer).
This is a manufacturer’s photo showing an older model.
To trim and chamfer cases, you simply insert them nose-first into the cartridge-specific case-holder. Erick offers a smart tip — He uses a die locking ring to position the cartridge holder (3:15). This can be locked in place. Erik says die locking rings work much better than the hex-nuts provided by Giraud (with the hex-nut, one must re-set cut length each time you change case-holders.)
The Giraud can be used in either horizontal or vertical modes. Erik prefers to have the trimmer aligned vertically, allowing him to push cases down on the trimmer head. But the trimming unit has twin sets of rubber feet, allowing horizontal or vertical orientation.
Improved Case-Holder Made with Chamber Reamer:
For his .284 Shehane, Erik had to create his own case-holder (Giraud does not make one for that wildcat cartridge). Erik used his chamber reamer. To his surprise, Erik found that the brass was easier to trim in the custom case holder (compared to the Giraud-made spring-loaded holders). With a perfect fit, trimming and case extraction went more smoothly and the process was easier on his hands. (See 9:00-10:00). Based on Erik’s experience, you may want to create your own custom case-holder.
Trim Bullet Meplats Also
With a special bullet-holder fitting and meplat cutter head, the Giraud power trimmer can be used to trim bullet meplats. Trimming meplats can help make the Ballistic Coefficents of a batch of bullets more consistent. Uniforming meplats is also often done as a first step in the process of “tipping” bullets to improve BC.
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Get an inside look at the how ammunition is made with this step-by-step production guide from Hornady. The video begins by showing the stages in production of a lead-core jacketed bullet with exposed tip, such as the Hornady Interlock. Next, at the 1:38″ time-mark, the video shows how cartridge cases are made, starting with small brass cups (photo right). The brass is lengthened in a series of stages involving annealing, drawing, polishing, and the formation of the case head with primer pocket. Finally, at the 2:40″ time mark, the video shows how bullets and powder are seated into cartridge cases on the Hornady assembly line. In the final production stages, the completed ammunition is tested and packaged.
Watch Ammo Production Video
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In our Shooters’ Forum a reader asked: “How much neck tension should I use?” This prompted a Forum discussion in which other Forum members recommended a specific number based on their experience, such as .001″, .002″, or .003″. These numbers, as commonly used, correspond to the difference between case-neck OD after sizing and the neck OD of a loaded round, with bullet in place. In other words, the numbers refer to the nominal amount of interference fit (after sizing).
While these commonly-used “tension numbers” (of .001″, .002″ etc.) can be useful as starting points, neck tension is actually a fairly complex subject. The actual amount of “grip” on the bullet is a function of many factors, of which neck-OD reduction during sizing is just one. Understanding these many factors will help you maintain consistent neck tension as your brass “evolves” over the course of multiple reloadings.
Neck Tension (i.e. Grip on Bullets) Is a Complex Phenomenon
While we certainly have considerable control over neck tension by using tighter or looser bushings (with smaller or bigger Inside Diameters), bushing size is only one factor at work. It’s important to understand the multiple factors that can increase or decrease the resistance to bullet release. Think in terms of overall brass-on-bullet “grip” instead of just bushing size.
One needs to understand that bushing size isn’t the beginning and end of neck tension questions, because, even if bushing size is held constant, the amount of bullet “grip” can change dramatically as the condition of your brass changes. Bullet “grip” can also change if you alter your seating depth significantly, and it can even change if you ultrasonically clean your cases.
Bullet grip is affected by many things, such as:
1. Neck-wall thickness.
2. Amount of bearing surface (shank) in the neck.
3. Surface condition inside of neck (residual carbon can act as a lubricant; ultrasonic cleaning makes necks “grabby”).
4. Length of neck (e.g. 6BR neck vs. 6BRX).
5. Whether or not the bullets have an anti-friction coating.
6. The springiness of the brass (which is related to degree of work-hardening; number of firings etc.)
7. The bullet jacket material.
8. The outside diameter of the bullet and whether it has a pressure ridge.
9. The time duration between bullet seating and actual firing (necks can stiffen with time).
10. How often the brass is annealed
— and there are others…
Seating Depth Changes Can Increase or Decrease Grip on Bullet
You can do this simple experiment. Seat a boat-tail bullet in your sized neck with .150″ of bearing surface (shank) in the neck. Now remove the bullet with an impact hammer. Next, take another identical bullet and seat it with .300″ of bearing surface in another sized case (same bushing size/same nominal tension). You’ll find the deeper-seated bullet is gripped much harder.
Neck-Wall Thickness is Important Too
I have also found that thinner necks, particularly the very thin necks used by many PPC shooters, require more sizing to give equivalent “grip”. Again, do your own experiment. Seat a bullet in a case turned to .008″ neckwall thickness and sized down .003″. Now compare that to a case with .014″ neckwall thickness and sized down .0015″. You may find that the bullet in the thin necks actually pulls out easier, though it supposedly has more “neck tension”, if one were to consider bushing size alone.
In practical terms, because thick necks are less elastic than very thin necks, when you turn necks you may need to run tighter bushings to maintain the same amount of actual grip on the bullets (as compared to no-turn brass). Consequently, I suspect the guys using .0015″ “tension” on no-turn brass may be a lot closer to the guys using .003″ “tension” on turned necks than either group may realize.
Toward a Better Definition of Neck Tension
As a convenient short-cut, we tend to describe neck tension by bushing size alone. When a guy says, “I run .002 neck tension”, that normally means he is using a die/bushing that sizes the necks .002″ smaller than a loaded round. Well we know something about his post-sizing neck OD, but do we really have a reliable idea about how much force is required to release his bullets? Maybe not… This use of the term “neck tension” when we are really only describing the amount of neck diameter reduction with a die/bushing is really kind of incomplete.
My point here is that it is overly simplistic to ask, “should I load with .001 tension or .003?” In reality, an .001″ reduction (after springback) on a thick neck might provide MORE “grip” on a deep-seated bullet than an .003″ reduction on a very thin-walled neck holding a bullet with minimal bearing surface in the neck. Bushing ID is something we can easily measure and verify. We use bushing size as a descriptor of neck tension because it is convenient and because the other important factors are hard to quantify. But those factors shouldn’t be ignored if you want to maintain consistent neck tension for optimal accuracy.
Consistency and accuracy — that’s really what this all about isn’t it? We want to find the best neck tension for accuracy, and then maintain that amount of grip-on-bullet over time. To do that you need to look not only at your bushing size, but also at how your brass has changed (work-hardened) with time, and whether other variables (such as the amount of carbon in the neck) have changed. Ultimately, optimal neck tension must be ascertained experimentally. You have to go out and test empirically to see what works, in YOUR rifle, with YOUR bullets and YOUR brass. And you may have to change the nominal tension setting (i.e. bushing size) as your brass work-hardens or IF YOU CHANGE SEATING DEPTHS.
Remember that bushing size alone does not tell us all we need to know about the neck’s true “holding power” on a bullet, or the energy required for bullet release. True bullet grip is a more complicated phenomenon, one that is affected by numerous factors, some of which are very hard to quantify.
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Repeated firings at stout pressures can cause primer pockets to grow in diameter. This can create an unsafe condition if your primers are not seating properly. Are your primer pockets “good to go”, or have they been pushed to the point of no return? Do you really know? Many guys try to gauge primer pocket tightness by “feel”, as they seat the primer. But that method isn’t precise. Now there’s a better way…
The folks at Ballistictools.com have created a handy set of precision-machined gauges that let you quickly and accurately check your primer pockets. These gauges are offered in two sizes — for large and small primer pockets. A two-piece set of both large and small gauges costs just $19.99. These gauges let you quickly measure the depth of a primer pocket, and check if the crimp has been removed properly. Most importantly, the gauge tells you if the primer pocket has opened up too much. One side of the gauge has an enlarged diameter plug. If that “No-Go” side fits in the primer pocket, you should ditch the case — it’s toast.
Precision ground from O-1 tool steel, these primer pocket gauges serve multiple functions. The inventor of these tools explains:
I created the prototype of this tool for my own use in brass processing. I needed a way to quickly and easily measure primer pockets that was reliable and did not require wasting a primer. This tool has been indispensable for me and I would never go back to the old method of uncertainty and guessing.
One side of this gauge is the “go” side which quickly tells you the depth of a primer pocket, whether any crimp is properly removed, and whether the primer pocket is loose. If it feels loose on the “go” side, use the other end of the tool, the “no go” side, to test to see if the primer pocket is too loose to hold a primer. If the no-go slides into the pocket, then you know to junk that brass.
Product tip from Boyd Allen. We welcome reader submissions.
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Butch Lambert of ShadeTree Engineering provided this tip. Butch notes that many 6 PPC benchrest group shooters also enjoy shooting in score matches. But to be really competitive in the BR for score game, that means shooting a 30BR, which has a wider, .308-class rim (0.4728″ diameter). Likewise, if you want to compete in 600-yard registered BR events or in varmint matches, you probably want to run a bigger case, such as the 6BR, 6mm Dasher, or 6-6.5×47. Those cartridges also have the larger 0.4728″ rims.
To convert a PPC-boltface action to shoot the bigger cases you can spend a ton of money and buy a new bolt. That can cost hundreds of dollars. The simpler solution is to turn down the diameter of the larger cases on a lathe. Butch explains: “We’ve seen plenty of interest in rebating case rims. This lets you shoot a 30BR in score matches using your PPC action. All you need is a new barrel. This saves buying another bolt, receiver, or rifle if you have a PPC boltface. Anyone who has access to a lathe can do this job pretty easily. Yesterday I turned 150 case in about an hour.” Below are photos of a rebated 6BR case, along with the lathe form tool Butch uses to rebate the case rims.
Cutting Head for Rebating Rims
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Powder Valley Inc. (PVI), a leading vendor of ammo and reloading components, warned us to be prepared for price hikes on Lapua-brand cartridge brass, bullets, and loaded ammunition:
“Lapua has announced a 4-8% price increase for 2015. Anyone who would like to order at 2014 prices please do so now. We will accept backorders on all Lapua from now until December 12 and these items will be filled at 2014 prices as soon as the items become available.”
Cutting to the chase, Powder Valley is saying it will honor current Lapua prices for back-orders, so long as you place your order by December 12th, 2014. So, if you need brass (or those ultra-consistent Lapua Scenar-L bullets), order now before the price goes up. Of course, you can also buy in-stock Lapua brass/bullets inventory from PVI and other major vendors including Bullets.com, Bruno Shooters Supply, Grafs.com, and Midsouth Shooters Supply.
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Bryce Towsley has authored an informative article on Reclaiming .223 Rem Brass. Writing for Shooting Illustrated Online, Towsley confesses: “I’m a brass horder…. I end every shooting match on my hands and knees. If the rest of the competitors want to litter the range with their discarded cases, I see it as my civic duty to clean up the mess.” If you burn through a lot of .223 Rem ammo on the varmint fields or in multi-gun matches, we suggest you read Towsley’s article.
Towsley advises that you need to be cautious with range pick-up brass: “Range brass is full of dirt, dust, sand and debris that can be damaging to loading dies, as well as causing other problems.” So, range pick-up brass must be cleaned and then sorted carefully. Towsley explains that you should toss brass that is badly dented, and you have to make sure to remove the primer pocket crimp in military brass. This can be done with a crimp reamer or a swaging tool such as the Dillon Super Swage 600. The latter works well, but Towsley cautions: “For the swager to work properly, you must sort the cases by brand and lot, and then readjust the swager for each new lot.”
Trimming Quantities of Brass
Before loading, “reclaimed” range brass should, of course, be full-length sized and you should trim all the brass to the same length. “Cases that are too long can cause all kinds of problems”, explains Towsley.
We envy the system Towsley uses to trim brass. He has a Dillon Rapid Trim 1200B set up on the top of a single-stage press: “You simply insert a case into the shell holder and raise the ram to trim it instantly. The process is so fast, it almost feels like cheating.” The Rapid Trim is a very neat gadget — it even has an attachment for a vacuum hose to remove the cuttings. The photo at right shows a 1200B installed on a Dillon progressive press.
We definitely recommend you read Bryce Towsley’s Reclaiming Range Brass Article from start to finish. The article offers useful advice that will help you reload any rifle cartridge — not just .223 Rem range brass. Towsley also showcases many good labor-saving devices that can speed up and simplify the process of bulk rifle cartridge reloading.
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Every year we anxiously await the new product announcement from Lapua. In 2014, Lapua brought out new bullets and new cartridge brass — .221 Fireball and .50 BMG. For 2015, Lapua once again brings out new brass offerings, this time three new flavors of cartridge brass, all made to Lapua’s exacting standards. First, Lapua will introduce factory 300 AAC Blackout (300 BLK) brass. This promises to take this highly-efficient, AR-friendly .30-caliber cartridge to another accuracy level. Second, Lapua will offer premium brass for the 7mm-08 cartridge, a very popular round among hunters and silhouette shooters. Lastly, in 2015, Lapua will produce 8x57mm JS brass. That’s good news for fans of this classic Mauser cartridge.
300 AAC Blackout Brass
Lapua’s Press release states: “Few cartridges have generated as much immediate interest as the 300 Blackout. Standardized by AAC, this diminutive cartridge is derived from the 223 Remington. Intended specifically for use in suppressed firearms, the versatility of the Blackout has appealed to a much broader range of shooters than just the audience for which it was originally designed. [Originally] intended to drive 220 grain bullets at subsonic velocities, the switch to lightweight bullets such as the 125 grain offerings delivers performance very similar to the venerable 7.62×39 cartridge. This makes the 300 Blackout potent enough for a wide range of shooting tasks, from certain tactical applications to many short range hunting situations involving medium-sized game. The ability for many 5.56mm/223 systems to be switched over to the 300 Blackout, merely by changing barrels, makes this an incredibly versatile combination. Lapua brings over nine decades of case manufacturing knowledge, precision and quality to the new Blackout, assuring the shooter of the very best performance.”
7mm-08 Remington Brass
Lapua notes that it’s new 7mm-08 brass is made to very high standards, benefiting hunters as well as competitors: “The 7mm-08 came to dominate the High Power Silhouette rifle game shortly after its introduction, offering a superb combination of power, light recoil and accuracy. Since then, it has also been used to win National Championships in High Power competition, and become a staple for hunters as well. With ballistic performance exceeding that of the time honored 7x57mm Mauser, but suited to a shorter action, the 7mm-08 is an ideal cartridge for most big game hunting. Lapua brings… state-of-the-art manufacturing methods, combined with old world craftsmanship, to the production of these cases. Primer pockets and flash holes are held to strict tolerances to withstand repeated firings and reloadings. After final necking of the case, they are finished with the proper anneal [for] accuracy and durability.” Lapua also notes that it offers two new 7mm Scenar bullets, which will work very well in the new 7mm-08 cartridge brass.
8x57mm JS Brass
Last but not least, Lapua is producing 8x57mm JS brass. Lapua notes that: “When the 8x57mm JS cartridge was introduced in 1905, its innovative use of a high velocity and relatively light weight pointed bullet design revolutionized infantry combat. An outgrowth on the original 8x57J military round, the 8x57mm JS round served the German military in both world wars, and became a popular sporting cartridge in any area where there was a strong German influence. From African plains game to European stag and boar, the 8mm Mauser has earned an enviable reputation as a big game round in a wide array of conditions. Accurate, versatile and powerful, the 8x57mm JS still serves the sporting community well for a host of hunting applications. In answer to the requests of the many devotees of this fine cartridge, Lapua is pleased to announce our introduction of the new 8x57mmJS case. The new 8x57mmJS will deliver the same accurate, reliable performance for which Lapua cases are world renowned. This means tough, durable cases that will not only withstand repeated loadings, but retain their accuracy shot after shot. [Lapua’s 8x57mm JS brass offers] very tight tolerances in neck wall concentricity and overall uniformity.”
See Lapua’s New Products at SHOT Show 2015
If you plan to attend SHOT Show in Las Vegas, stop by and visit the Lapua Exhibit (booth #11929). With luck, samples of the new 7mm-08, 300 BLK, and 8×57 JS brass will be available to view. Lapua engineers will be on hand to talk about Lapua brass and bullets, and explain the production processes that make Lapua brass so durable and consistent. In recent years, in the world of centerfire competition, Lapua brass has absolutely dominated the winner’s circles as well as the record-books.
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Many shooters, particular those who shoot vintage military rifle matches, reload once-fired military cartridge brass. This brass may be high-quality and stout, but you may encounter a primer crimp* that interferes with the seating of a new primer. There are a variety of dedicated, military-crimp tools on the market, such as Dillon’s excellent Super Swage 600 tool that “rolls the crimp away”. But the Dillon tool costs $100.95 and takes quite a bit of room on your reloading bench. If you don’t want to drop a C-note and give up valuable bench space — here’s another (much cheaper) solution.
If you already have a Wilson case trimmer set-up, you can ream away those military crimps using an affordable Wilson accessory — the Primer Pocket Reamer (large #PPR-210, small #PPR-175). This $32.99 accessory is used in conjunction with a Wilson case trimmer and case-holder as shown below.
On his Riflemans Journal website, German Salazar shows how to use the Wilson primer pocket reamer to remove military crimps on Lake City .30-06 cartridge brass. German explains: “The case goes into the Wilson case-holder, the same one used for case trimming, and the reamer replaces the trimmer head in the tool base. The threaded rod on the left side, which is normally used to regulate trim length has no use for this operation and it is simply backed out. Hold the case-holder as you turn the reamer into the primer pocket, it cuts easily and quickly. The reamer will stop cutting when the proper depth is reached.”
Do you really need to do this operation with military-crimped brass? Yes. German cautions: “any attempt to prime the case without removing the crimp will simply result in a mangled primer that cannot be expected to fire and certainly won’t fire reliably.”
*Why does military brass has a primer crimp? German answers: “The crimp is nothing more than an intentional deformation of the case around the primer pocket, the purpose of which is to retain the primer in the case despite high pressure situations in machine guns and other automatic weapons where a loose primer may cause a malfunction. As reloaders, our task is to get rid of the remnants of the crimp in order to allow re-priming the case.”
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German Salazar has written a very thorough guide to measuring nearly all the critical dimensions of cartridge brass. In his Measuring the Case article, on his Rifleman’s Journal website, German reviews the tools and techniques required to measure everything from case overall length to case neck concentricity. Step-by-step, German shows how to measure: Case Length, Case Body length (below neck), Neck Diameter, Headspace, Base Diameter, Neck Thickness, and Case Neck Concentricity.
If you are an “advanced reloader” or want to be, you should read German’s article. Not only does German explain the most common measuring procedures, he highlights some alternative methods you might not have tried yet. The article also links to related discussions of more complex measurement tasts, such as determining case body wall thickness variation.
Even if you’re not a competitive shooter, measuring your brass can provide important safety benefits. As German explains in the conclusion of his article: “There are obviously a lot of measurements that can be taken on the cartridge case and in some cases, more than one way to take them. However, the first two that any new reloader must learn are case length and neck clearance, these two are safety concerns and if overlooked can results in serious damage to the rifle and injury to you.”
Chances are that many of you have packed away your ammo and shooting supplies for the winter. Maybe you put your brass in a storage bin that might also contain solvents, old rags, or used bore swabs. Well, if you use any ammonia-based solvents, we suggest you separate the brass and ammo and keep it away from potential ammonia vapors. This is because long-term exposure to ammonia fumes can cause cracks to form in your brass. This can lead to case ruptures and possible injury.
This case-cracking phenomenon has been called Season Cracking, a form of stress-corrosion cracking of brass cartridge cases. Season cracking is characterized by deep brittle cracks which penetrate into affected components. If the cracks reach a critical size, the component can suddenly fracture, sometimes with disastrous results. If the concentration of ammonia is very high, then corrosion is much more severe, and damage over all exposed surfaces occurs. The brass cracking is caused by a reaction between ammonia and copper that forms the cuprammonium ion, Cu(NH3)4, a chemical complex which is water-soluble. The problem of cracking can also occur in copper and copper alloys such as bronze.
Season Cracking was originally observed by the British forces in India a century ago. During the monsoon season, military activity was reduced, and ammunition was stored in stables until the dry weather returned. Many brass cartridges were subsequently found to be cracked, especially where the case was crimped to the bullet. In 1921, in the Journal of the Institute of Metals, the phenomenon was explained by Moor, Beckinsale, and Mallinson. Apparently ammonia from horse urine, combined with the residual stress in the cold-drawn metal of the cartridges, was responsible for the cracking.
Don’t store ammunition (or brass) for long periods in a box or container holding ammoniated solvents:
The Australia Department of Defense (AUSDOD) has also explored the problem of brass cracking caused, at least in part, by exposure to ammonia. A study was done to see whether the amount of cracking (from ammonia exposure) varied according to the duration and temperature of the annealing process used on the brass. CLICK HERE to read AUSDOD Research Report.
Story idea from Boyd Allen. We welcome reader submissions.
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Do you shoot a .308 Winchester (and who doesn’t)? Well here’s a great deal on Lapua .308 Win brass, the best you can buy. Ultra-consistent, Lapua brass stays strong for many reloading cycles, even with stout loads. Lapua is the choice of most F-TR competitors who shoot the .308 Win in competition.
The .308 Win Palma version brass (item BL11071) features small primer pockets. Some people believe the small primer pockets help the cases deliver a lower Extreme Spread (ES) and (maybe) withstand high pressures for more loading cycles. YMMV, but we do like the small-primer-pocket .308 Win Lapua brass and it’s our first choice for target applications.
Both types of Lapua .308 Winchester brass are now available at very attractive prices from Bullets.com: $61.95 for large primer pocket brass, $69.95 for small pocket brass. This cartridge brass is in stock today and ready to ship. CLICK HERE to order.
10/1/2014 Update: Sale Inventories of the Small Primer Pocket .308 Win Palma brass are sold out. You can still buy this brass, but the regular price is $79.95 per 100 cases.
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The folks at PMA Tool, makers of arbor presses, neck-turning tools, and other case-prep tools, offer some good advice about case trimming on the PMA Tool Blog. Here we reprint a PMA blog post that explains case trimming basics and helps you choose the right case-trimming tool for your needs.
Case Trimming Basics
Trimming the cartridge case to the proper length is a crucial step in case preparation that should not be overlooked or underestimated. The cartridge case or the rifle can be damaged, or even worse you get badly injured. In most instances cases should be trimmed after firing and sizing. Trimming new brass is necessary for a lot of wildcats and can be beneficial in some instances, but by and large, trimming new brass is not necessary for most situations (unless you are neck-turning). Cases should be trimmed after you have sized the case, because the expander ball on the decapping pin can (and will) stretch the neck. Those of us who neck size should get into the habit of trimming after sizing as well. This is a good rule of thumb to go by, and hopefully it will keep you safe during the reloading and shooting process.
There are so many case trimmers out there that work, deciding which one is right for you can be confusing. Even though I have trimmed thousands of cases, using about every method possible, I can’t answer the question of what case trimmer is right for you because of all the variables that may be involved. I can, however shed some light on the subject.
The two most popular designs of trimmers either index (1) off the base or the head of the case, (2) off the shoulder or datum line of the case. There are pros and cons to each and it all depends on what you are willing to live with.
Indexing off the Base (Case Head)
Let’s talk about the first one I have listed, indexing off the base, or the head of the case. The pros to this method are that you can achieve a very accurate over all length and that is after all, what it is all about. The cons to this method are that you can get some variation doing it this way. Let me explain, the base is not always square to the body or can be damaged during firing especially if it is fired through a military style rifle with a very aggressive ejector. These cases should be discarded, but sometimes they can be overlooked. This condition can lead to an over all length that is incorrect. The case head being out of square will be corrected upon firing, however that case will wind up being shorter than the rest of your cases, possibly creating a difference in the neck tension on the bullet. The more you can do to eliminate variables in your reloads the better off you are going to be. This method can also be very slow, and if the user gets careless the result will be a inconsistent over all length.
Indexing off the Shoulder (Datum Line)
The second method I mentioned, trimming off the shoulder or the datum line of the case, has its pros as well. I have found this to be the quickest of the methods and very accurate as well. After the case has been sized through the die the dimensions (particularly the headspace) of the cases are usually very uniform and exact, this allows the case to be trimmed by indexing off the shoulder. This method can be done very quickly, by hand, or by powering either the case, or the trimmer. You also don’t have to worry about the case heads being out of square with the body using this method. Generally the trimming time is cut in half, and this leads to greater focus on the job, without becoming careless. [Editor’s Note: The World’s Finest Trimmer (WFT) is one power device that indexes off the shoulder datum. It works fast and is very precise. The new WFT 2 Model with interchangeable trim chambers works with multiple cartridge types.]
The choice is yours to make. I hope that this was some help to you, whether you are looking for your first trimmer or looking to replace the trimmer you have. Just remember to always put safety first and accuracy second, and you will start making little bug holes in no time.
Story Tip by EdLongrange. User Submissions are welcome.
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When we first ran this story a while back, it generated great interest among readers. By popular request, we’re reprinting this story, in case you missed it the first time around. — Editor
Precision shooters favor premium brass from Lapua, Norma, or RWS. (Lake City also makes quality brass in military calibers.) Premium brass delivers better accuracy, more consistent velocities, and longer life. Shooters understand the importance of good brass, but many of us have no idea how cartridge cases are actually made. Here’s how it’s done.
The process starts with a brass disk stamped from strips of metal. Then, through a series of stages, the brass is extruded or drawn into a cylindrical shape. In the extrusion process the brass is squeezed through a die under tremendous pressure. This is repeated two or three times typically. In the more traditional “draw” process, the case is progressively stretched longer, in 3 to 5 stages, using a series of high-pressure rams forcing the brass into a form die. While extrusion may be more common today, RWS, which makes some of the most uniform brass in the world, still uses the draw process: “It starts with cup drawing after the bands have been punched out. RWS cases are drawn in three ‘stages’ and after each draw they are annealed, pickled, rinsed and subjected to further quality improvement measures. This achieves specific hardening of the brass cases and increases their resistance to extraordinary stresses.” FYI, Lapua also uses a traditional draw process to manufacture most of its cartridge brass (although Lapua employs some proprietary steps that are different from RWS’s methods).
After the cases are extruded or drawn to max length, the cases are trimmed and the neck/shoulder are formed. Then the extractor groove (on rimless cases) is formed or machined, and the primer pocket is created in the base. One way to form the primer pocket is to use a hardened steel plug called a “bunter”. In the photos below you see the stages for forming a 20mm cannon case (courtesy OldAmmo.com), along with bunters used for Lake City rifle brass. This illustrates the draw process (as opposed to extrusion). The process of draw-forming rifle brass is that same as for this 20mm shell, just on a smaller scale.
River Valley Ordnance explains: “When a case is being made, it is drawn to its final draw length, with the diameter being slightly smaller than needed. At this point in its life, the head of the draw is slightly rounded, and there are no provisions for a primer. So the final drawn cases are trimmed to length, then run into the head bunter. A punch, ground to the intended contours for the inside of the case, pushes the draw into a cylindrical die and holds it in place while another punch rams into the case from the other end, mashing the bottom flat. That secondary ram holds the headstamp bunter punch.
The headstamp bunter punch has a protrusion on the end to make the primer pocket, and has raised lettering around the face to form the headstamp writing. This is, of course, all a mirror image of the finished case head. Small cases, such as 5.56×45, can be headed with a single strike. Larger cases, like 7.62×51 and 50 BMG, need to be struck once to form a dent for the primer pocket, then a second strike to finish the pocket, flatten the head, and imprint the writing. This second strike works the brass to harden it so it will support the pressure of firing.”
Thanks to Guy Hildebrand, of the Cartridge Collectors’ Exchange, OldAmmo.com, for providing this 20mm Draw Set photo. Bunter photo from River Valley Ordnance.
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Here’s an article from a couple seasons back. For safety reasons, we are republishing the story. Recently, one of our contributing writers experienced a similar problem at the range. Here, German Salazar looks at the causes for case-head separation, and he recommends a procedure for inspecting your cases.
On his Riflemans’ Journal blog, German Salazar wrote an excellent article about cartridge Case-Head Separation. We strongly recommend that you read this article. German examines the causes of this serious problem and he explains 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. German scribed 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.
One great tip offered by German Salazar involves using a bent paper clip to detect potential case wall problems. Slide the paper clip inside your case to check for thin spots. German 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!”
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This new tool trims cases quickly, with precision control over case length via a micrometer-type dial. The folks at ACT Tactical have developed an easy-to-use compact case trimmer called the TRIM-IT. Crafted from 6061-T6 aluminum, this sturdy case trimmer comes with a 100% lifetime guarantee. The $97.50 TRIM-IT features a micrometer that’s built into the unit itself. Caliber-specific inserts (called “Caliber Dies”) index off the case shoulder.
The TRIM-IT can work with any hand-drill or drill press. Once you get the hang of it, you can trim a case in 7-8 seconds — that gives you a production rate of 400+ cases per hour. The TRIM-IT delivers repeatable precision to plus/minus one-thousandth. This unit also holds its cut-length setting, unlike some other trimmers which require frequent adjustment.
The basic unit ships with two caliber dies, for .223 and .308. Other listed caliber dies include 6.8 SPC, .300 BLK, .30-06, 30-30 Win, 300 Win Mag, 7MM REM, 7.62x54R, and 8MM Mauser. Other cartridge types can be custom-ordered from EZTrimit.com. To change dies, simply loosen the set screw on the TRIM-IT, take the caliber die out, add another one, and tighten the screw — quick and easy.
The built-in micrometer is great. The handy dial gives you a positive, repeatable length setting quickly — no fiddling with locking rings or spacers. Once you get the ring set properly, the cut lengths are consistent from the first case to the last. Expect your case OAL spread to be about +/- .001″ (starting with full-length-sized cases with uniform rim to shoulder lengths). For more information, email sales [at] eztrimit.com or call (562) 602-0080. You can see how the Trim-It device works in the video below.
Video Shows Trim-it Set-Up and Operation
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What is “Overbore”? That’s a question rifle shooters can debate to no end. This article from our archives proposes one way to identify “overbore cartridges”. We think the approach outlined here is quite useful, but we know that there are other ways to define cartridges with “overbore” properties. Whenever we run this article, it stimulates a healthy debate among our readers — and that is probably a good thing.
Forum Member John L. has been intrigued by the question of “overbore” cartridges. People generally agree that overbore designs can be “barrel burners”, but is there a way to predict barrel life based on how radically a case is “overbore”? John notes that there is no generally accepted definition of “overbore”. Based on analyses of a wide variety of cartridges, John hoped to create a comparative index to determine whether a cartridge is more or less “overbore”. This, in turn, might help us predict barrel life and maybe even predict the cartridge’s accuracy potential.
John tells us: “I have read countless discussions about overbore cartridges for years. There seemed to be some widely accepted, general rules of thumb as to what makes a case ‘overbore’. In the simplest terms, a very big case pushing a relatively small diameter bullet is acknowledged as the classic overbore design. But it’s not just large powder capacity that creates an overbore situation — it is the relationship between powder capacity and barrel bore diameter. Looking at those two factors, we can express the ‘Overbore Index’ as a mathematical formula — the case capacity in grains of water divided by the area (in square inches) of the bore cross-section. This gives us an Index which lets us compare various cartridge designs.”
OVERBORE INDEX Chart
So what do these numbers mean? John says: “My own conclusion from much reading and analysis is that cartridges with case volume to bore area ratio less than 900 are most likely easy on barrels and those greater than 1000 are hard on barrels.” John acknowledges, however, that these numbers are just for comparison purposes. One can’t simply use the Index number, by itself, to predict barrel life. For example, one cannot conclude that a 600 Index number cartridge will necessarily give twice the barrel life of a 1200 Index cartridge. However, John says, a lower index number “seems to be a good predictor of barrel life”.
John’s system, while not perfect, does give us a benchmark to compare various cartridge designs. If, for example, you’re trying to decide between a 6.5-284 and a 260 Remington, it makes sense to compare the “Overbore Index” number for both cartridges. Then, of course, you have to consider other factors such as powder type, pressure, velocity, bullet weight, and barrel hardness.
Overbore Cases and Accuracy
Barrel life may not be the only thing predicted by the ratio of powder capacity to bore cross-section area. John thinks that if we look at our most accurate cartridges, such as the 6 PPC, and 30 BR, there’s some indication that lower Index numbers are associated with greater inherent accuracy. This is only a theory. John notes: “While I do not have the facilities to validate the hypothesis that the case capacity to bore area ratio is a good predictor of accuracy — along with other well-known factors — it seems to be one important factor.”
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