As an Amazon Associate, this site earns a commission from Amazon sales.











July 29th, 2022

Velocity Per Inch in .223 Rem — Barrel Cut-Down Test Results

.223 Rem Cut-Down Test barrel UMC m855

Most of us own a .223 Rem rifle. Now, thanks to our friends at Rifleshooter.com we can assess exactly how velocity changes with barrel length for this popular cartridge.

Rifleshooter.com performed an interesting test, cutting the barrel of a .223 Rem rifle from 26″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .223 Rem/5.56 ammo were chron’d at each barrel length. The Rifleshooter.com team that conducts these tests has a full-service gun shop, 782 Custom Gunworks — visit 782guns.com.

READ RifleShooter.com 5.56/.223 Barrel Cut-Down Test Article »

Test Barrel Lost 25.34 FPS Per Inch (.223 Rem Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. The average speed loss of the four types of .223/5.56 ammo, with a 9.5″ shortening of barrel length, was 240.75 fps total (from start to finish). That works out to an average loss of 25.34 fps per inch.

5.56/.223 Barrel Cut-Down Speed Test 26″ to 16.5″ Start FPS at 26″ End FPS at 16.5″ Total Loss Average Loss Per Inch
UMC .223 55gr 3182* 2968 214 22.5 FPS
Federal M193 55gr 3431 3187 244 25.7 FPS
Win m855 62gr 3280 2992 288 30.3 FPS
Blk Hills .223 68gr 2849 2632 217 22.8 FPS

*There may have been an error. The 25″ velocity was higher at 3221 fps.

See inch-by-inch Barrel Cut-Down Velocity Data HERE »

Rifleshooter.com observed: “Cutting the barrel from 26″ to 16.5″ resulted in a velocity reduction of 214 ft/sec with the UMC 223 55-grain cartridge, 244 ft/sec with the Federal M-193 cartridge, 288 ft/sec with the Winchester M855 cartridge and 217 ft/sec with the Back Hills 223 68-grain match cartridge.”

How the Test Was Done
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel-mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 45.7° F.”

CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers.

See More Barrel Cut-Down Tests on Rifleshooter.com
Rifleshooter.com has performed barrel cut-down tests for many other calibers/chamberings including 6mm Creedmoor, .308 Winchester, and .338 Lapua Magnum. See these test results at Rifleshooter.com.

.308 Win barrel length cut test

Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .223/5.56 test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″ we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was longer than Rifleshooter.com’s .223 Rem start length. Velocity loss may be more extreme with shorter barrel lengths. And, of course, different cartridge types and powder/bullet combinations will yield different results.

Permalink Bullets, Brass, Ammo, Gunsmithing, Tech Tip No Comments »
July 27th, 2022

Don’t Fry Your Barrels — Monitor Barrel Heat with Temp Strips

Barrel Heat Temp Temperature gauge strip McMaster Carr

August is almost here, so we’re near the peak heat of summer. We are already seeing extremely hot conditions in many areas of the country. You never want your barrels to get too hot, which can happen more quickly in summertime. Accuracy suffers when barrels over-heat, and excessive heat is not good for barrel life. So how do you monitor your barrel’s temperature? You can check if the barrel is “warm to the touch” — but that method is not particularly precise. There is a better way — using temperature-sensitive strips. McMaster.com (an industrial supply house) offers stick-on temp strips with values from 86° F to 140° F. A pack of ten (10) of these horizontal strips (item 59535K13) costs $13.16. That’s a mere $1.32 per barrel for strips — cheap insurance for your precious barrels. For best barrel life, try to stay under 120 degrees F.

Barrel Heat Temp Temperature gauge strip McMaster Carr

NOTE: On the McMaster.com website, you’ll need to scroll down to the multi-use “Temperature Indicating Labels”. Then click on the horizontal label and select item 59535K13, as shown below.

Barrel Heat Temp Temperature gauge strip McMaster Carr

Forum member Nomad47 says: “I have temperature strips (bought at McMaster-Carr) on all my barrels. I try not to shoot when the barrel gets to 122 degrees or higher[.]” Here are photos of the McMaster-Carr temp strips on Nomad47’s customized Savage.

Barrel Heat Temp Temperature gauge strip McMaster Carr

Bad things can happen if your barrel gets too hot. First, with some barrels, the point of impact (POI) will shift or “walk” as the barrel heats up excessively. Second, even if the POI doesn’t change, the groups can open up dramatically when the barrel gets too hot. Third, if the barrel is very hot, the chamber will transfer heat to your loaded cartridge, which can lead to pressure issues. Finally, there’s considerable evidence that hot barrels wear out faster. This is a very real concern, particularly for varmint shooters who may shoot hundreds of rounds in a day. For this reason, many varminters switch among various guns, never letting a particular barrel get too hot.

Neconos.com offers BAR-L Temp Strips that visually display heat readings from 86 to 140 degrees. Think of these strips as compact, unbreakable thermometers that monitor barrel heating.

Put a strip on the side of the barrel and the barrel’s temp will be indicated by a stripe that changes from black to green. There is also a “general purpose” strip that reads to 196 degrees (see bottom row). The Benchrest model strip (86°F to 140°F) is in the middle. These Bar-L temp strips cost $12.70 each, or $25.00 for a 3-pack.

NOTE: These strips can be permanently fixed to the barrel with the heavy-duty clear plastic tape strip provided with the BAR-L Temp strip.

Permalink Competition, Gear Review, Tech Tip 1 Comment »
July 27th, 2022

Modern Advancements in Long Range Shooting, Vol. III Available

Bryan Litz Applied ballistics Modern Advancements Long range shooting III Volume 3

The Science of Accuracy Academy is now accepting pre-orders for the newest book in the Modern Advancements series by Bryan Litz. The book, titled Modern Advancements in Long Range Shooting, Volume III can be pre-ordered now for $44.95. Pre-ordered books are expected to ship by early September.

The Modern Advancements series is an ongoing journal of the R&D activities at Applied Ballistics. Theories of ballistics are explored “myth-buster” style with extensive live fire testing. Employing state-of-the-art ballistic instrumentation including Doppler Radar and high-speed (Phantom) video, the Applied Ballistics team has made key insights about ballistics which are then shared through books and the Science of Accuracy Academy.

This 3rd Volume of the series has 13 Chapters. The book features four main parts: Part 1: Precision Testing, Part 2: Advanced Handloading, Part 3: Doppler Radar Testing, and Part 4: Miscellaneous.

Bryan Litz Applied ballistics Modern Advancements Long range shooting III Volume 3

Pre-orders for individuals and dealers opened July 26, 2022, and end when the books ship in late August or early September. During the pre-order phase, subscribers of The Science of Accuracy Academy will get a $20 off coupon for the new book. Other ballistics books by Bryan Litz are available through the Science of Accuracy Academy STORE.

Bryan Litz Applied ballistics Modern Advancements Long range shooting III Volume 3

About Applied Ballistics
Applied Ballistics’ mission is to be a complete, unbiased source of external ballistics information for long-range shooters. We’re highly active in R&D, constantly testing new claims, products, and ideas for potential merit and dispensing with the marketing hype which can make it so difficult for shooters to master the challenging discipline of long-range shooting.

We believe in the scientific method and promote mastery through an understanding of the fundamentals. Our work serves the shooting community via instructional materials which are easy to understand, and products such as ballistic software which runs on many platforms. If you’re a long-range shooter who’s eager to learn about the science of your craft, we’re here for you.

Permalink Bullets, Brass, Ammo, New Product, Tech Tip No Comments »
July 26th, 2022

Protect Your Vision — Smart Advice about Safety Eyewear

Safety Eyewear 6.5 Guys 65guys.com

Proper eye protection is ‘must-have’ gear for shooting sports. In addition to providing reliable impact protection, good shooting glasses should be comfortable, fog-free, and not interfere with your preferred hearing protection. Those who require corrective lenses also need to consider the various options available. In a past episode of their Weekly Gear Review, the 6.5 Guys discuss a variety of shooting glasses they have tried, including examples from DeCot, Oakley, and Wiley-X. Ed and Steve outline the key considerations when choosing eye protection, and then review practical aspects of eyewear design and construction that enhance comfort and functionality in the field.

READ FULL ARTICLE ON 65Guys.com »

The 6.5 Guys (Ed and Steve) offer a number of smart tips consider safety eyewear, helping you select the most effective safety glasses at an affordable price. Here are the 6.5 Guys’ KEY Take-aways when choosing shooting glasses, including prescription eyewear:

Key Things To Consider When Choosing Eye Protection

1. Avoid polarized lenses or lenses that reduce light transmission significantly (except for action shooting in very bright conditions with large, close targets).

2. Avoid frame designs that interfere with prone shooting.

3. Avoid designs that easily fog.

4. Avoid frame designs with thicker temples that are uncomfortable to wear underneath hearing protection.

5. Select lenses with an appropriate degree of ballistic protection. CLICK HERE to learn more about eyewear safety standards.

6. When you get your prescription, be sure your ophthalmologist includes the interpupillary distance. This is a critical measurement particularly for heavier prescriptions.

7. If you have a complicated prescription select a vendor who will actually spend time with you to address any concerns.

Horrific .50 BMG Kaboom — Eye Saved by Protective Eyewear

Think you don’t need eye protection? Watch this video starting at 4:10. The screw-on barrel “cap” (chamber closure) of the .50 BMG action flies into the shooter’s face. Without eye protection the shooter would have definitely lost his right eye. (See video at 5:20 for analysis).

Safety First — Your Eyes Are Irreplaceable
Safety Eyewear 6.5 Guys 65guys.comAccurate shooting begins and ends with the human eye. Your career as a marksman could be cut short if you don’t use good eye protection every time you go to the range and/or handle a firearm.

Every year, 1,000,000 people suffer serious eye injuries. Shooting is hazardous; it is estimated that there are 30,000 firearms-related eye injuries each year (if you include paintball sports.) After paintball, general hunting accidents comprise most firearms-related eye injuries.

Quality eye protection need not be expensive. You can find comfortable, ANSI Z87.1-certified shooting glasses for under $10.00.

If you select shooting glasses carefully, and ensure that your eyewear is safety-certified, inexpensive shooting glasses can perform very well. But you need to avoid cheap, soft-plastic lenses that claim “impact resistance” without satisfying a testing standard.

For more comprehensive information on safety eyewear, read the AccurateShooter’s Guide to Eye Protection for Shooters.

Permalink - Articles, - Videos, Optics, Tech Tip No Comments »
July 22nd, 2022

Clean Brass Effectively with Ultrasonic Cleaning Machines

Ultrasonic Cleaning RCBS Ultrasound .308 Winchester 7.62x51 brass casings

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, $406.99 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 $180.72 at Midsouth Shooters.

Permalink - Videos, Bullets, Brass, Ammo, Gear Review, Tech Tip No Comments »
July 22nd, 2022

Monitor Barrel Heat with Handy, Infrared Thermometers

infrared pocket pen battery thermometer

Monitor Barrel Heat with Pocket Infrared Gauges
It’s the middle of summer, and temperatures are HOT around the country. That makes it more important than ever to monitor your barrel temp when at the range. You NEVER want to run the barrel of a precision rifle too hot. Excessive barrel heat kills accuracy, increases copper fouling, and can cause rapid barrel throat wear. Over the years people have devised various means to cool their barrels — from electric fans to dunking in tubs of ice water.

But how do you know if your barrel is too hot? Consider a “non-contact” thermometer that reads your barrel’s “infrared signature”. The small pocket-sized, non-contact Infrared (IR) thermometers are ideal for shooters at the range or in the prairie dog fields. Such thermometers are handy and inexpensive. You can buy these mini IR pen thermometers for under $15.00 from Amazon, Walmart, and other vendors.

infrared pocket pen battery thermometer

Pen-Sized Thermometers
Just 3.2″ long, and weighing an ounce, these handy IR pen thermometers are small enough to carry in your pocket, and will easily stow in any range bag/box. The Yidexin unit, sold by both Amazon and Walmart, can measure from -58 to 428 °F (-50 to 220 °C). You can also find considerably larger hand-held IR thermometers for industrial applications. These can measure up to 716 °F. But for quick measurement of barrel temps, we prefer the small pen IR thermometers that fit in a pocket. A little IR thermometer like this is a gadget that every serious shooter should have. Given the cost of replacing barrels these days (up to $700 for barrel, chambering and fitting), can you afford NOT to have a temp gauge for your match or varmint barrel?

TECH TIP — How to Get More Consistent Readings
When using IR Thermometers on shiny steel barrels, sometimes the polished surface throws off the beam, causing inconsistent readings. You can solve this problem by simply putting a piece of masking tape on the area where you take your reading. Some other folks use a grease pencil to create a non-reflective spot to read. Forum Member Jon B. says: “I used an Exergen infrared in the HVAC industry. Without the grease crayon they sold, you couldn’t get an accurate reading with shiny metals.”

Permalink Gear Review, Hot Deals, Tech Tip No Comments »
July 21st, 2022

Primer Chain Reaction — Flash Ignites More Primers in Tool Tray

primer flash explosion Hornady handheld primer tool kaboom

Here is an important safety reminder for readers who employ hand priming tools with trays of multiple primers. In this instance a primer detonated while being seating in a pistol cartridge case. This caused a “flash-over” which instantly ignited multiple other primers in the tray. That, in turn, caused a small explosion which broke the tray and Hornady Handheld Priming Tool. The user, a Forum member, reported this last summer in our Shooters’ Forum.

primer flash explosion Hornady handheld primer tool kaboomReport by Forum Member about Primer Flash-Over Incident
I had a small scare the other day while reloading. My experience might be a helpful reminder to people to keep safe and follow proper procedures and not be sloppy.

A primer popped (went off) when being seated and (while hot) flashed over into the tray causing other primers in the tray to detonate. That, in turn, broke my Hornady Handheld Priming Tool and injured my hand.

Here is my loading area after the incident. Note the damage to the hand priming tool. I’m not not sure where the rest of the pieces are.

primer flash explosion Hornady handheld primer tool kaboom

Injuries to User — Multiple Cuts on Hand and Forearm
This photo shows the resulting cuts to hand. Fortunately they seem superficial. Note — I was wearing latex gloves so my hand had some protection.

primer flash explosion Hornady handheld primer tool kaboom

The blast also blew my glasses off my face and they landed about six feet away. Be careful folks and wear your eye protection! EDITOR: Guys — This is yet more compelling evidence why handloaders should always wear eye protection!

More Details — Primers Were Federal LP, Case Primer Pockets Had Been Checked
The forum member noted: “Just in case people are interested, I didn’t notice anything different from usual. Cases were Privi Partizan (PPU) factory brass on their fourth firing. The primers were Federal Large Pistol. The cases had been ultrasonic cleaned and the primer pockets checked prior to priming. I had primed around 50 cases during this session before the accident.”

Here is a close-up of “flashed” primers — note the empty but dented cups and triangular “anvils”:

primer flash explosion Hornady handheld primer tool kaboom

This incident happened using a Hornady Handheld Priming Tool, as shown below.

primer flash explosion Hornady handheld primer tool kaboom

Two other Forum members reported feeding issues with this particular Hornady handheld priming tool and one other member, Kiwi Greg, suffered a multi-primer detonation causing injury: “I had the same thing happen a few years ago now with the same Hornady hand primer with 50-75 [Federal 215M primers] in the tray. Made a bit of a mess of both my hands, blew primers and tray all around my large workshop. Scared the [heck] out of my employee who was near me at the time. Some stitches, bandages and it was all good, [but with] some wicked scars… I think a primer had turned side-on when being put into Bertram .408 CT brass which had nice tight pockets and required more force than usual. I use RCBS [priming tools] now with a flat bar that slides across to prevent sympathetic detonations. I hadn’t heard of it before, but found out it wasn’t that uncommon after it happened.”

Thanks to Boyd Allen for finding this post.
Permalink Bullets, Brass, Ammo, Reloading, Tech Tip 4 Comments »
July 21st, 2022

3D Ammo Animation — Great Video Shows How Pistols Works

GECO Ruag Ammotec RWS ammo 3D animation video

Here’s a very cool 3D Animation showing pistol rounds being fired. Computer-generated graphics provide a look inside the cartridge at the moment of ignition as the primer fires and the flame front moves through the ignited powder. It’s really kind of mesmerizing. If you’ve every wondered just what happens inside your cartridges the moment that firing pin strikes, then watch this video…

Watch Video to See Handgun Ammo Being Chambered and Fired:

Mute Enabled — Click Speaker Icon to Hear Audio. Firing Sequence Starts at 1:28.

GECO Ruag Ammotec RWS ammo 3D animation videoThis animated video from German ammo-maker GECO (part of the Swiss RUAG group of companies) reveals the inside of a pistol cartridge, showing jacket, lead core, case, powder and primer. Employing advanced 3D rendering and computer graphics, the video shows an X-ray view of ammo being loaded in a handgun, feeding from a magazine.

Then it really gets interesting. At 1:28 – 1:50 you’ll see the firing pin strike the primer cup, the primer’s hot jet streaming through the flash-hole, and the powder igniting. Finally you can see the bullet as it moves down the barrel and spins its way to a target. This is a very nicely-produced video. If you’ve ever wondered what happens inside a cartridge when you pull the trigger, this video shows all. They say “a picture’s worth a thousand words”… well a 3D video is even better.

GECO Ruag Ammotec RWS ammo 3D animation video

GECO Ruag Ammotec RWS ammo 3D animation video

GECO Ruag Ammotec RWS ammo 3D animation video

Permalink - Videos, Bullets, Brass, Ammo, Handguns, Tech Tip No Comments »
July 20th, 2022

Color-Coat Bullet Tips to Better Define Long-Range Groups

sharpie felt marker bullet color tip painting group paper target

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.

sharpie felt marker bullet color tip painting group paper target

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:

sharpie felt marker bullet color tip painting group paper target

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:

sharpie felt marker bullet color tip painting group paper target

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.

Permalink Bullets, Brass, Ammo, Shooting Skills, Tech Tip No Comments »
July 20th, 2022

.223 Rem vs. 5.56x45mm NATO — What You Need to Know

.223 Rem Remington 5.56 SAAMI CIP 5.56x45 5.56x45mm NATO cartridge ammo pressure test luckygunner ultimatereloader Gavin Gear

Probably the most popular centerfire rifle round in the Western Hemisphere is the .223 Remington and its metric match, the 5.56x45mm. Though many folks use “.223 Rem” and “5.56×45″ interchangeably, there are some meaningful differences in specifications for the original .223 Rem and the 5.56x45mm cartridge, as adopted by the U.S. military and NATO armies. The default chamber throats are slightly different and the .223 Rem is rated at 55,000 PSI vs. 62,366 PSI for the 5.56x45mm.*

.223 Rem vs 5.56x45mm — Key Differences
There is a truly outstanding, very thorough article on the subject, published by LuckyGunner.com.** This involved extensive testing, with pressure monitors, of 5.56x45mm ammo in .223 Rem chambers. Those tests revealed the peak pressures. Here is one of the ammo test charts:

.223 Rem Remington 5.56 SAAMI CIP 5.56x45 5.56x45mm NATO cartridge ammo pressure test luckygunner ultimatereloader Gavin Gear

NOTE: “The observed chamber pressure for Federal XM855 5.56mm ammunition in a .223 Rem chamber exceeded .223 maximum pressures, but not by a massive amount. The ninth shot (the red line) was an underpowered cartridge which exhibited significantly lower velocity and pressure than the other rounds, so it was excluded from the average velocity and pressure numbers for this chamber.”

And if you’re curious, LuckyGunner also fired .223 Rem ammo in a 5.56x45mm NATO-chambered AR15 rifle. As you would expect, the peak pressures were significantly lower, but the .223 Rem ammo still cycled the semi-auto AR-platform rifle perfectly well:

.223 Rem Remington 5.56 SAAMI CIP 5.56x45 5.56x45mm NATO cartridge ammo pressure test luckygunner ultimatereloader Gavin Gear

READ FULL LuckyGunner .223 Rem vs. 5.56x45mm ARTICLE »

UltimateReloader.com Explains .223 Rem vs. 5.56x45mm
To explain the key differences between the .223 Rem and 5.56x45mm cartridges our friend Gavin Gear of UltimateReloader.com has created a very thorough 12-minute video. This covers the cartridge specifications and explains key considerations for hand-loaders. Gavin also addresses the oft-asked question “Can I shoot 5.56x45mm ammo in my .223 Rem chamber?” Gavin’s video is definitely worth watching. In fact, this is one of the most popular videos Gavin has ever created — it has been watched nearly 4.5 million times on YouTube.

What Exactly Is the 5.56x45mm NATO Cartridge?
The 5.56×45mm NATO is a rimless bottle-necked intermediate cartridge family standardized by NATO with development work by FN Herstal. It consists of the SS109, SS110, and SS111 cartridges. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries.

Bullet diameter: 5.70 mm (0.224 in)
Maximum pressure (EPVAT): 430.00 MPa (62,366 psi)
Maximum pressure (SCATP 5.56): 380.00 MPa (55,114 psi)
Case length: 44.70 mm (1.760 in)
Rifling twist: 178 mm or 229 mm (1 in 7 in)
Parent case: .223 Remington (M193)

Ammo-Maker Federal Premium Compares .223 Rem and 5.56x45mm
Here is a video from ammo-maker Federal Premium explaining the difference between .223 Remington and 5.56x45mm NATO. Federal states that you may experience excessive pressures when firing a 5.56x45mm in a standard .223 Remington chamber:

One leading gunwriter has addressed the question of shooting 5.56x45mm ammo in .223 Rem chambers. He advocates caution (for more info, SEE pressure tests by LuckyGunner.com):

“I have received a slew of questions — many from first time AR-type rifle buyers — about the .223 Rem and the 5.56×45 mm NATO cartridges. Can I shoot 5.56×45 mm NATO in my .223 and vice-versa? Are these the same cartridge?

Externally, the two cartridge cases are identical. The main differences are that 5.56×45 mm NATO operates at a higher chamber pressure (about 60,000 PSI versus 55,000 PSI on the .223 Rem.) and the 5.56’s chamber is slightly larger than that of the .223 Rem. Also, the throat or leade is longer in the 5.56×45 mm chamber. What does this mean? You should not shoot 5.56×45 mm NATO out of a rifle that is chambered in .223 Rem [with a standard short throat]. And be aware that some .223 Rem ammunition will not reliably cycle through some AR-style .223 Rem rifles, but it usually does. As a matter of fact, I have not encountered any difficulty with current .223 Rem. loads cycling through a 5.56 mm AR-style rifle.” — Mark Keefe, Editor, American Rifleman


* According to the official NATO proofing guidelines, the 5.56×45mm NATO case can handle up to 430.0 MPa (62,366 psi) piezo service pressure. The U.S. SAAMI lists Maximum Average Pressure (MAP) for the .223 Remington cartridge as 55,000 psi (379.2 MPa) piezo pressure with deviation of up to 58,000 psi (399.9 MPa). The chamber for military 5.56×45mm NATO has a longer throat prior to the bullet contacting the rifling which results in lower pressures when firing 5.56×45mm NATO ammunition. If 5.56×45mm NATO is used in rifles chambered for .223 Remington the bullet will be engraving the rifling when chambered. which can increase pressures past SAAMI Max levels. NOTE: The C.I.P. standards for the C.I.P. civilian .223 Remington chamber are much closer to the military 5.56×45mm NATO chamber.

** The full-length LuckyGunner article is well worth reading. It even provides specifications for a number of .223 Rem reamer types, and compares the original .223 Rem, the 5.56x45mm NATO, and the modern .223 Wylde chamberings.

Permalink Bullets, Brass, Ammo, Reloading, Tactical, Tech Tip No Comments »
July 19th, 2022

Long-Term Powder Storage — What You Need to Know

Western Powders Blog SAAMI Storage

SUMMARY: Powder can have a very long shelf life. You need to watch for changes in smell and color. A reddish tinge, almost like rust on the powder, is a bad sign, as is a foul odor, not to be confused with a normal chemical smell. Either of these signs indicate it is time to dispose of your powder by means other than shooting.

Ever wondered about the stability of the propellants in your reloading room? There are some important things you should know about powder storage, to ensure consistent powder performance and safety. Western Powders (which has been acquired by Hodgdon) published an informative Q & A series entitled Dear Labby: Questions for our Ballistics Lab . Here are some excerpts that pertain to powder storage and shelf life. Worried that your powder may be too old? Western’s experts explain how to check your propellants for warning signs.

Proper Powder Storage

Q: I live in southern Arizona where it is very hot. I am told powders will become unstable if stored in an area not air-conditioned. My wife says no powder or primers in the house. Can powder be stored in a refrigerator? What about using a fireproof safe? I would appreciate your ideas. — M.C.

Lab Answer: SAAMI guidelines are pretty clear on issues of storage. They recommend storing smokeless powder in containers that will not allow pressure to build if the powder is ignited — ruling out gun safes and refrigerators.

CLICK HERE to Read SAAMI Guidelines for Powder Storage (PDF)

In their original containers, the lifespan of smokeless powders is quite long, even in hot, arid climates. In fact the lifespan is typically longer than the average handloader would need to store them. Stored safely in a garage or outbuilding, your powder should last years. If you see the powder developing a reddish tint, or giving off a foul odor, it is time to discard it.

Clumps in Powder Container

Q: I ordered some of your Accurate 1680 powder back about in December. I just now opened it … and it is full of clumps. My knowledge tells me that means moisture. Am I wrong? I just now broke the seal and it has been stored in a ammo can with desiccant packs around it and a dehumidifier running 14-16 hours a day. I can’t imagine this being my fault, if this does indicate moisture. I don’t know if the pink part on the label is suppose to be red or not, but it is definitely pink, so if it was red I am wondering if I was shipped an old container? I hope that this isn’t bad and I am stuck with it…

Lab Answer: All powder contains a certain amount of moisture. When the powder is stored or during shipping, it can go through temperature cycles. During the cycling, the moisture can be pulled to the surface and cause clumping. Clumping can also be caused by static electricity if too dry or the powder has limited graphite content. You can break up the clumps before metering and they shouldn’t be a problem. This will not affect the powder performance, so your product is fine. Accurate 1680 labels are designed in Pink. As a side note, specification for testing powder is at 70° F and 60% humidity.

Shelf Life and Packaging Dates

Q: Does powder ever get to old to use and what identifying marks does your company put on the canister for when it is made, You have helped me out a while ago when I asked about keeping my cowboy shooting under 950 fps and it works great less stress on the hand and the recoil is very minimum. — R.B.

Lab Answer: On one pound bottles, the number is on the corner in a silver box. If the powder was poured today, it would read 012815 followed by a lot number. The whole number would look something like 012815749. Eight pound bottles have a sticker on the bottom with an obvious date code. The lot number appears above the date.

Western Powders Blog SAAMI Storage

Permalink - Articles, Reloading, Tech Tip 3 Comments »
July 18th, 2022

5 Degrees of Doom — The Real Risk of Unintended Down-Range Impacts from Slightly Elevated Muzzles

Gun Angle long range

In our Shooters’ Forum, there was an discussion about a range that was threatened with closure because rifle over-shoots were hitting a farm building over two miles from the firing line. One reader was skeptical of this, asking “how’s that possible — were these guys aiming at the stars?” Actually, you may be surprised. It doesn’t take much up-angle on a rifle to have a bullet land miles down-range. That’s why it’s so important that hunters and target shooters always orient their barrels in a safe direction (and angle). Shooters may not realize how much a small tilt of the barrel (above horizontal) can alter a bullet’s trajectory.

How many degrees of muzzle elevation do you think it would take to hit a barn at 3000 yards? Ten Degrees? Twenty Degrees? Actually the answer is much less — for a typical hunting cartridge, five to seven degrees of up-angle on the rifle is enough to create a trajectory that will have your bullet impacting at 3000 yards — that’s 1.7 miles away!

Gun Angle long range

Five degrees isn’t much at all. Look at the diagram above. The angle actually displayed for the up-tilted rifle is a true 5.07 degrees (above horizontal). Using JBM Ballistics, we calculated 5.07° as the angle that would produce a 3000-yard impact with a 185gr .30-caliber bullet launched at 2850 fps MV. That would be a moderate “book load” for a .300 Win Mag deer rifle.

Here’s how we derived the angle value. Using Litz-derived BCs for a 185gr Berger Hunting VLD launched at 2850 fps, the drop at 3000 yards is 304.1 MOA (Minutes of Angle), assuming a 100-yard zero. This was calculated using a G7 BC with the JBM Ballistics Program. There are 60 MOA for each 1 degree of Angle. Thus, 304.1 MOA equals 5.068 degrees. So, that means that if you tilt up your muzzle just slightly over five degrees, your 185gr bullet (2850 fps MV) will impact 3000 yards down-range.

Figuring Trajectories with Different Bullets and MVs
If the bullet travels slower, or if you shoot a bullet with a lower BC, the angle elevation required for a 3000-yard impact goes up, but the principle is the same. Let’s say you have a 168gr HPBT MatchKing launched at 2750 fps MV from a .308 Winchester. (That’s a typical tactical load.) With a 100-yard zero, the total drop is 440.1 MOA, or 7.335 degrees. That’s more up-tilt than our example above, but seven degrees is still not that much, when you consider how a rifle might be handled during a negligent discharge.

Think about a hunter getting into position for a prone shot. If careless, he could easily touch off the trigger with a muzzle up-angle of 10 degrees or more. Even when shooting from the bench, there is the possibility of discharging a rifle before the gun is leveled, sending the shot over the berm and, potentially, thousands of yards down-range.

Hopefully this article has shown folks that a very small amount of barrel elevation can make a huge difference in your bullet’s trajectory, and where it eventually lands. Nobody wants to put holes in a distant neighbor’s house, or worse yet, have the shot cause injury.

Let’s go back to our original example of a 185gr bullet with a MV of 2850 fps. According to JBM, this projectile will still be traveling 687 fps at 3000 yards, with 193.7 ft/lbs of retained energy at that distance. That’s more than enough energy to be deadly.

Permalink - Articles, Shooting Skills, Tech Tip 2 Comments »
July 17th, 2022

Basics of Bullet Seating with Hand Dies and Inline Arbor Press

arbor press hand die

Creedmoor Sports has released a series of helpful “how-to” videos in its new InfoZone web page. In the latest InfoZone video Bill Gravatt shows how to seat bullets using L.E. Wilson Hand Dies and an Arbor Press. The basic process is simple, particularly with a micrometer-top seating die. That makes it easy to adjust and set seating depth. Before you start seating bullets, you want to adjust the height of the arbor so the stroke is appropriate to the height of your die.

Bill Gravatt Shows How to Use Hand Seating Dies — Creedmoor INFOZONE

ARBOR PRESS TECHNIQUE: When using an arbor press, smooth is good. You don’t want to slam the handle down quickly. Try to repeat the same motion each time. You can also experiment by seating the bullet part way, then rotate the cartridge (in the die) and do the final seating with a second stroke. If your arbor press has a force gauge, note both the max value of the gauge needle and how it moves as you seat the bullet. If the needle spikes too rapidly, or bounces back and forth irregularly, set that cartridge aside and/or mark it. You could have neck tension issue with that case or some other fault. You might even have a bad bullet. That’s rare, but can happen. The key to success is moving the press arm in a smooth motion every time, maintaining the same down-pressure with each cartridge.

Here Bill Gravatt Offers a Simple Tip for Adjusting Wilson Seating Dies

One of our Forum readers asked “How can I get a custom in-line seater for my new rifle?”. First, we would say that, if you are not shooting an unusual Wildcat, check first to see if L.E. Wilson makes a stainless Micrometer Seater Die for your rifle. These dies are a joy to use, and we’ve found the fit to be exceptionally good with many calibers. Typically priced from $90-$100, Wilson stainless micrometer-top seaters are available for dozens of cartridge types: .204 Ruger, 20 BR, .222 Rem, .223 Rem, 22 PPC, 22 BR, .22-250, .223 WSSM, 6 PPC, 6mmBR, 6XC, 243 Win, .243 WSSM, 25 WSSM, 6.5×47 Lapua, 6.5 Creedmoor, 6.5-284, 26 Nosler, .270 WSM, 7mm-08, .284 Win, 28 Nosler, 7mm RUM, 30 BR, 30 IHMSA, .308 Win, .300 WinMag, .338 Edge (and MORE).

If you do want a custom seater die, the process is relatively simple. Purchase a die blank from Wilson and have your gunsmith run the chambering reamer in. Forum member Gunamonth explains: “I start with a Wilson seating die blank. They’re available from Sinclair and other vendors. Just run the reamer in. For some of my rifles, where I wanted the stainless die with the micrometer adjustment, I bought a smaller die and had the smith ream it with the chamber reamer. That’s how I had my 6 Dasher and 6mm AI seaters made. With the Dasher I stared with a 6mmBR Micrometer die.”

Wilson inline seater die and blank

SEATER STEM TIP: If, on your seated bullets, you are seeing a sharp line around the jacket near the ogive, you may want to smooth out the leading edge of the Wilson seater stem (see above left). Do this by putting a little lapping compound on one bullet and manually spin this around in the stem. Without much effort you’ll have a smooth bullet/stem interface.

Micrometer Top Add-on
We really like micrometer tops on a seating die. But what if Wilson doesn’t make a micrometer top seater for your chambering? Don’t despair, Brownells sells a $39.99 Sinclair Micrometer Top that can be added to Wilson standard seaters or to a custom seater die made from a Wilson die blank.

Wilson inline seater die and blank

Permalink - Videos, Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
July 17th, 2022

Flash-Hole Fixer — How to Clear Flash-Hole Obstructions

Flash-hole reamer

Even with high-quality brass from Lapua, Peterson, Norma, Alpha and RWS, occasionally you may find one or two cases per box which have a small flake or obstruction in the flash-hole. This will appear like a thin crescent on one side of the flash hole (see photo). You should inspect ALL new brass before loading to identify any pieces with a partially-obstructed flash hole. It’s a good idea to remove any flake or thin crescent left as an artifact of the flash-hole forming process. Because the flash-hole itself is normally centered and of the correct diameter, it is not necessary to ream the flash-hole to a larger diameter. All you really need to do is remove the small obstruction(s). This can be done quickly with inexpensive tools.

Use a Small Pin Vise to Remove Flash-Hole Obstructions
Folks have asked if there is a tool that can remove obstructions from a Lapua small, BR-sized flash hole without opening the hole size. The Lapua PPC/BR flash hole is spec’d at 1.5mm, which works out to 0.059055″. Most of the PPC/BR flash-hole uniforming tools on the market use a 1/16″ bit which is nominally 0.0625″, but these often run oversize — up to 0.066″.

If you want to just clear out any obstructions in the flash hole, without increasing the flash hole diameter, you can use an inexpensive “pin vise” with an appropriate drill bit. For $0.99, eHobbyTools.com sells a 1.5mm drill bit, item 79186, that matches the Lapua flash hole exactly. Other vendors offer a #53 pin vise drill bit that measures .0595″ or .060″ (depending or source). An 0.0595″ bit is close enough. You can find pin vises and these small-diameter drill bits at hobby stores.

Pin vises Lapua Flash hole

For quite some time, Sinclair Int’l has sold a similar device for small (PPC and BR-size) flash holes. Like the 07-3081 unit for large flash holes, the 073000 Reamer for small flash holes works from the outside, so it can index off the primer pocket. It reams to .0625″, and also costs $29.99. The standard dimension for Lapua 220 Russian and 6mmBR flash holes is 1.5mm or .0590″. This tool will permit standard-size decapping rods with .0625″ tips to work without binding. However, note that both Forster and Redding normally supply .057″ decapping pins with their PPC and BR dies. So, it is NOT necessary to ream your Lapua BR/PPC flashholes, unless you prefer to do so for uniformity. It IS, however, a good idea to check BR/PPC flash holes for burrs before loading the first time.

AccurateShooter Sinclair Flash Hole Reamer

NOTE: If you purchase either the 073081 or 073000 Sinclair Flash Hole Reamer tools, we recommend you mic the cutter tip before you process a bunch of cases. Sometimes a tip comes through that is oversize. This will ream the flash holes larger than you may intend.

Permalink Gear Review, Reloading, Tech Tip No Comments »
July 15th, 2022

For Better Bullet Seating — Try Lapping Inside of Seating Stems

Erik Cortina bullet seating stem polish lap lathe

Here’s a simple task you can do that will give your seater die a more perfect fit to your match bullets. You can lap the inside of the seater stem so that it matches the exact profile of the bullet. This spreads out the seating force over a larger area of the bullet jacket. That allows smoother, more consistent seating, without putting dents, creases, or sharp rings in your bullets.

Erik Cortina bullet seating stem polish lap lathe

This process is demonstrated here by our friend Erik Cortina of Team Lapua-Brux-Borden. Erik, one of the nation’s top F-Class shooters and a skilled machinist, explains: “Here I’m lapping my new seater die stem with lapping compound. I chuck up a bullet in the lathe and lap the inside of the seating stem. I put lapping compound on the bullet and also in the stem. You can do the same with a hand drill and bore paste. You can see in the piture below how much contact area the stem has on the bullet after being lapped. This bullet is a Berger 7mm 180-grain Hybrid. ”

Erik Cortina bullet seating stem polish lap lathe

READ Related Article on Polishing Seating Die Stems »

Q1: Is Lapping Seating Stems really necessary?

It can be helpful but it’s not necessary to make your seating stem an exact match to a bullet, particularly if you’re loading hunting or varmint rounds. But it is helpful to do some mild internal stem polishing. This should eliminate any ring (or dent) that forms on the bullet jacket during seating.

bullet seating stem lapping Erik Cortina
Photo credit Sierra Bullets.

Sharp edges on a seating stem can cause a ring to be pressed into the bullet jacket — especially with compressed loads that resist downward bullet movement.

Q2: Is there any down-side to the process?

Not really. However, if you shoot many different bullet types for a particular cartridge, you may not want to conform the stem aggressively to one particular bullet design. Lightly lap the inside of the stem to remove burrs/sharp edges but leave it at that. A light lap will prevent a ring forming when seating bullets.

bullet seating stem lapping Erik Cortina
Photo credit Sierra Bullets.

Permalink - Articles, - Videos, Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
July 13th, 2022

Gone in SIX Seconds — The Brutal Truth of Short Barrel Life

Stopwatch barrel life

This thought-provoking article has been one of the most popular Daily Bulletin features in recent years. We are republishing this story today for readers who may have missed it the first time around…

Here’s a little known fact that may startle most readers, even experienced gunsmiths: your barrel wears out in a matter of seconds. The useful life of a typical match barrel, in terms of actual bullet-in-barrel time, is only a few seconds. How can that be, you ask? Well you need to look at the actual time that bullets spend traveling through the bore during the barrel’s useful life. (Hint: it’s not very long).

Bullet-Time-in-Barrel Calculations
If a bullet flies at 3000 fps, it will pass through a 24″ (two-foot) barrel in 1/1500th of a second. If you have a useful barrel life of 3000 rounds, that would translate to just two seconds of actual bullet-in-barrel operating time.

Ah, but it’s not that simple. Your bullet starts at zero velocity and then accelerates as it passes through the bore, so the projectile’s average velocity is not the same as the 3000 fps muzzle velocity. So how long does a centerfire bullet (with 3000 fps MV) typically stay in the bore? The answer is about .002 seconds. This number was calculated by Varmint Al, who is a really smart engineer dude who worked at the Lawrence Livermore Laboratory, a government think tank that develops neutron bombs, fusion reactors and other simple stuff.

On his Barrel Tuner page, Varmint Al figured out that the amount of time a bullet spends in a barrel during firing is under .002 seconds. Al writes: “The approximate time that it takes a 3300 fps muzzle velocity bullet to exit the barrel, assuming a constant acceleration, is 0.0011 seconds. Actual exit times would be longer since the bullet is not under constant acceleration.”

We’ll use the .002 number for our calculations here, knowing that the exact number depends on barrel length and muzzle velocity. But .002 is a good average that errs, if anything, on the side of more barrel operating life rather than less.

So, if a bullet spends .002 seconds in the barrel during each shot, and you get 3000 rounds of accurate barrel life, how much actual firing time does the barrel deliver before it loses accuracy? That’s simple math: 3000 x .002 seconds = 6 seconds.

Stopwatch barrel lifeGone in Six Seconds. Want to Cry Now?
Six seconds. That’s how long your barrel actually functions (in terms of bullet-in-barrel shot time) before it “goes south”. Yes, we know some barrels last longer than 3000 rounds. On the other hand, plenty of .243 Win and 6.5-284 barrels lose accuracy in 1500 rounds or less. If your barrel loses accuracy at the 1500-round mark, then it only worked for three seconds! Of course, if you are shooting a “long-lived” .308 Win that goes 5000 rounds before losing accuracy, then you get a whopping TEN seconds of barrel life. Anyway you look at it, a rifle barrel has very little longevity, when you consider actual firing time.

People already lament the high cost of replacing barrels. Now that you know how short-lived barrels really are, you can complain even louder. Of course our analysis does give you even more of an excuse to buy a nice new Bartlein, Krieger, Shilen etc. barrel for that fine rifle of yours.

Permalink Bullets, Brass, Ammo, Gunsmithing, Tech Tip 1 Comment »
July 12th, 2022

Reloading Manuals — Hard Copy Resources for Handloaders

reloading hand-loading reload data manual sierra berger hornady lyman

It’s great to be able to access online load data for your cartridges. You can quickly get load data for a particular powder and bullet weight. However, there are times when we prefer to consult old-fashioned printed/bound load manuals. The primary reason is that manuals produced by bullet- and tool-makers will, for a particular cartridge, include data for powders from multiple manufacturers. Having a single source can save you time and trouble. For example, if you want to find 6.5 Creedmoor loads using H4350 (Hodgdon), Reloder 16 (Alliant), and N150 (Vihtavuori) you would have to visit three different powder-maker websites, one after another. OR you can pick up a modern load manual and find everything in one place.

There are many excellent printed load manuals on the market. We have used the Berger Manual, Sierra Manual, Speer Manual, Lyman Manual, and Hornady Manual. We like the Berger and Sierra manuals for match rifle cartridges, and the Lyman and Hornady manuals for hunting loads and pistol cartridges. Unfortunately, the popular binder-format Sierra Manual is currently back-ordered. Likewise the excellent Nosler Reloading Guide 9 is currently out of stock.

The Lyman Reloading Manuals have earn praise over the years:
“Every other reloading book I’ve used favors their own bullets over every other manufacturers. With Lyman you get an honest representation of a wide variety of different… manufacturers. [Lyman has] a ton of reloading data on just about any bullet style you can imagine. I’ve tried a wide range of their recipes and everyone I’ve tried has been spot on. The overall breadth of information this book covers is impressive.” Review by RangetoReal.com.

Along with the Lyman 50th Edition Manual, here are other recommended Reloading Manuals:

Here Are Four General Instructional Books That Cover Reloading Procedures:

POWDER BURN RATE TABLE

Here is the most recent powder burn rate chart from Hodgdon/IMR that we could find. Click links below to access printable PDF. Note, some readers have suggested a couple powder ranking issues in the table. However, this is the latest official version from the IMR website, released in November 2019.


POWDER BURN RATE TABLE from HODGDON.COM

Hodgdon IMR Winchester Burn Rate Powder speed table relative table chart

CLICK HERE to Download Chart as PDF File »

Permalink Bullets, Brass, Ammo, Reloading, Tech Tip No Comments »
July 11th, 2022

Making of Cartridge Brass — Production Process Revealed

deep draw cartridge brass animated gif

Rifle cartridge brass manufacturingPrecision Benchrest and F-Class shooters favor premium brass from Lapua, Norma, Peterson, 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.

Top Deep-Draw Ram Illustration from Demsey Mfg.

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).

RWS Brass Cartridge Draw process

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.

20mm cartridge brass forming

20mm Draw Set Oldammo.com

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.

Lake City Brass bunterThe 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.

Permalink - Videos, Bullets, Brass, Ammo, Tech Tip No Comments »
July 9th, 2022

Handy Small Magnifiers Are Great for Many Handloading Tasks

Magnifying lens LED light relaoding

pocket fold-out magnifierWhat is the most-used piece of equipment on this Editor’s reloading bench? No it’s not my Rock-Chucker press, my priming tool, or even my calipers. The one item in near-constant use is a small, folding magnifying glass. Mine folds into a square case and offers 4X viewing with an 8X bifocal insert. With this handy tool I can inspect case mouths for burrs, check primer pockets, inspect meplats, and look for flaws on bullet jackets. I also use the magnifier to see rifling marks on bullets seated into the rifling, or check my bolt for galling. The number of uses is nearly endless. I keep one magnifier at my reloading bench and another in my range kit.

Folding magnifiers are so handy yet inexpensive that you should own a couple spares (including one in the range box). I bought my magnifier in a book-store, but you can also find them on Amazon.com and FoldingMagnifier.com starting at under $2.00. To see inside cases and dies and view fine details, consider the 5X Meromore Folding Magnifier with a built-in, battery-powered LED light, plus a 11X high-magnification insert.

With a decent small magnifier, you can easily see any minute flaws in your barrel crowns. That’s important because crown damage can cause hard-to-diagnose accuracy issues. We’ve known guys who spend weeks tinkering with loads, when the real problem was a worn-out or damaged crown.

The slide-out iLumen8, shown at left in top photo, offers 3X power with built-in illumination. An “Amazon’s Choice” item, this palm-sized magnifier is $20.75 on Amazon.

Permalink Optics, Reloading, Tech Tip No Comments »
July 8th, 2022

Berger Twist Rate Stability Calculator — Optimize Bullet RPM

Berger twist rate calculator

Berger Twist-Rate Stability Calculator
Berger twist rate calculatorOn the Berger Bullets website you’ll find a handy Twist-Rate Stability Calculator that predicts your gyroscopic stability factor (SG) based on mulitiple variables: velocity, bullet length, bullet weight, barrel twist rate, ambient temperature, and altitude. This cool tool tells you if your chosen bullet will really stabilize in your barrel.


CLICK HERE to Go to TWIST RATE CALCULATOR PAGE »

How to Use Berger’s Twist Rate Calculator
Using the Twist Rate Calculator is simple. Just enter the bullet DIAMETER (e.g. .264), bullet WEIGHT (in grains), and bullet overall LENGTH (in inches). On its website, Berger conveniently provides this info for all its bullet types. For other brands, we suggest you weigh three examples of your chosen bullet, and also measure the length on three samples. Then use the average weight and length of the three. To calculate bullet stability, simply enter your bullet data (along with observed Muzzle Velocity, outside Temperature, and Altitude) and click “Calculate SG”. Try different twist rate numbers (and recalculate) until you get an SG value of 1.4 (or higher).

Gyroscopic Stability (SG) and Twist Rate
Berger’s Twist Rate Calculator provides a predicted stability value called “SG” (for “Gyroscopic Stability”). This indicates the Gyroscopic Stability applied to the bullet by spin. This number is derived from the basic equation: SG = (rigidity of the spinning mass)/(overturning aerodynamic torque).

Berger twist rate calculator

If you have an SG under 1.0, your bullet is predicted not to stabilize. If you have between 1.0 and 1.1 SG, your bullet may or may not stabilize. If you have an SG greater than 1.1, your bullet should stabilize under optimal conditions, but stabilization might not be adequate when temperature, altitude, or other variables are less-than-optimal. That’s why Berger normally recommends at least 1.5 SG to get out of the “Marginal Stability” zone.

In his book Applied Ballistics For Long-Range Shooting (3rd Ed.), Bryan Litz (Berger Ballistician) recommends at least a 1.4 SG rating when selecting a barrel twist for a particular bullet. This gives you a safety margin for shooting under various conditions, such as higher or lower altitudes or temperatures.

Story idea from EdLongrange. We welcome reader submissions.
Permalink Bullets, Brass, Ammo, Competition, Tech Tip No Comments »