April 23rd, 2021

GREAT Video on Making Brass and Precision Ammo — Watch Now

Norma factory ammo production video

Guys — honestly, if you do anything today on this site, watch this video. You won’t be disappointed. Guaranteed. This is a very informative (and surprisingly entertaining) video. Every serious hand-loader should watch this video to see how cartridge cases and loaded ammo are made. Your Editor has watched the video 5 times now and I still find it fascinating. The camera work and editing are excellent — there are many close-ups revealing key processes such as annealing and head-stamping.

VERY Informative Video Show Cartridge Brass and Ammunition Production:

Norma has released a fascinating video showing how bullet, brass, and ammunition are produced at the Norma Precision AB factory which first opened in 1902. You can see how cartridges are made starting with brass disks, then formed into shape through a series of processes, including “hitting [the cup] with a 30-ton hammer”. After annealing (shown at 0:08″), samples from every batch of brass are analyzed (at multiple points along the case length) to check metal grain structure and hardness. Before packing, each case is visually inspected by a human being (3:27″ time-mark).

The video also shows how bullets are made from jackets and lead cores. Finally, you can watch the loading machines that fill cases with powder, seat the bullets, and then transport the loaded rounds to the packing system. In his enthusiasm, the reporter/narrator does sometimes confuse the term “bullets” and “rounds” (5:00″), but you can figure out what he means. We definitely recommend watching this video. It’s fascinating to see 110-year-old sorting devices on the assembly line right next to state-of-the art, digitally-controlled production machinery.

Video tip by EdLongrange. We welcome reader submissions.
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April 23rd, 2021

Do Chron Your Factory Ammo — Stated Velocities May Be Wrong

muzzle velocity applied Ballistics MV chronograph

Why You CANNOT Rely on the MV Printed on the Ammo Box!
When figuring out your come-ups with a ballistics solver or drop chart it’s “mission critical” to have an accurate muzzle velocity (MV). When shooting factory ammo, it’s tempting to use the manufacturer-provided MV which may be printed on the package. That’s not such a great idea says Bryan Litz of Applied Ballistics. Don’t rely on the MV on the box, Bryan advises — you should take out your chrono and run your own velocity tests. There are a number of reasons why the MV values on ammo packaging may be inaccurate. Below is a discussion of factory ammo MV from the Applied Ballistics Facebook Page.

Five Reasons You Cannot Trust the Velocity on a Box of Ammo:

1. You have no idea about the rifle used for the MV test.

2. You have no idea what atmospheric conditions were during testing, and yes it matters a lot.

3. You have no idea of the SD for the factory ammo, and how the manufacturer derived the MV from that SD. (Marketing plays a role here).

4. You have no idea of the precision and quality of chronograph(s) used for velocity testing.

5. You have no idea if the manufacturer used the raw velocity, or back-calculated the MV. The BC used to back track that data is also unknown.

1. The factory test rifle and your rifle are not the same. Aside from having a different chamber, and possibly barrel length some other things are important too like the barrel twist rate, and how much wear was in the barrel. Was it just recently cleaned, has it ever been cleaned? You simply don’t know anything about the rifle used in testing.

2. Temperature and Humidity conditions may be quite different (than during testing). Temperature has a physical effect on powder, which changes how it burns. Couple this with the fact that different powders can vary in temp-stability quite a bit. You just don’t know what the conditions at the time of testing were. Also a lot of factory ammunition is loaded with powder that is meter friendly. Meter friendly can often times be ball powder, which is less temperature stable than stick powder often times.

3. The ammo’s Standard Deviation (SD) is unknown. You will often notice that while MV is often listed on ammo packages, Standard Deviation (normally) is not. It is not uncommon for factory ammunition to have an SD of 18 or higher. Sometimes as high as 40+. As such is the nature of metering powder. With marketing in mind, did they pick the high, low, or average end of the SD? We really don’t know. You won’t either until you test it for yourself. For hand-loaded ammo, to be considered around 10 fps or less. Having a high SD is often the nature of metered powder and factory loads. The image below is from Modern Advancements in Long Range Shooting: Volume II.

muzzle velocity applied Ballistics MV chronograph

4. You don’t know how MV was measured. What chronograph system did the manufacturer use, and how did they back track to a muzzle velocity? A chronograph does not measure true velocity at the muzzle; it simply measures velocity at the location it is sitting. So you need to back-calculate the distance from the chrono to the end of the barrel. This calculation requires a semi-accurate BC. So whose BC was used to back track to the muzzle or did the manufacturer even do that? Did they simply print the numbers displayed by the chronograph? What kind of chronograph setup did they use? We know from our Lab Testing that not all chronographs are created equal. Without knowing what chronograph was used, you have no idea the quality of the measurement. See: Applied Ballistics Chronograph Chapter Excerpt.

5. The MV data may not be current. Does the manufacturer update that data for every lot? Or is it the same data from years ago? Some manufacturers rarely if ever re-test and update information. Some update it every lot (ABM Ammo is actually tested every single lot for 1% consistency). Without knowing this information, you could be using data for years ago.

CONCLUSION: Never use the printed MV off a box of ammo as anything more than a starting point, there are too many factors to account for. You must always either test for the MV with a chronograph, or use carefully obtained, live fire data. When you are using a Ballistic Solver such as the AB Apps or Devices integrated with AB, you need to know the MV to an accuracy down to 5 fps. The more reliable the MV number, the better your ballistics solutions.

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April 23rd, 2021

Don’t Get Caught Short — Make Sure Your Barrels Are Legal Length

short barrel barreled rifle shotgun NSA tax stamp ATF legal brief guncollective.com

The Legal Brief is a feature of TheGuncollective.com that focuses on firearms rules and regulations. In this Legal Brief video, Attorney Adam Kraut explains key State and Federal regulations governing firearms, and explains how to ensure compliance with all applicable laws.

This five-minute video explains barrel length rules for rifles and shotguns, and also explains the best (and most fool-proof) methods to measure your barrel. In addition, the video explains how to measure firearm overall length. A rifle or shotgun which is less than 26 inches overall can also be classified as a “Short-barreled” rifle/shotgun subject to the NFA. NOTE: Under federal law “If the rifle or shotgun has a collapsible stock, the overall length is measured with the stock EXTENDED”.

Highlights of LEGAL BRIEF Discussion of Barrel Length and Firearm Overall Length

The ATF procedure to measure the length of a barrel is to measure from the closed bolt or breech face to the furthest end of the barrel or permanently attached muzzle device. ATF considers a muzzle device that has been permanently attached to be part of the barrel and therefore counts towards the length.

How to Measure Barrel Length: Drop [a] dowel or rod into the barrel until it touches the bolt or breech face, which has to be closed. Mark the outside of the rod at the end of the muzzle crown (if you don’t have a permanently attached muzzle device) or at the end of the muzzle device if it is permanently attached. Remove the rod and measure from the mark to the end of the rod. That is your barrel length[.]

Remember, if the barrel length is less than 16 inches, it is possible that the firearm could be a short barrel rifle (if you are building a rifle or it is already on a rifle) and if the barrel length is less than 18 inches, it is possible the firearm could be a short barrel shotgun (again if you are building a shotgun or it is already a shotgun). Both of these firearms would be subject to the purview of the National Firearms Act and would require the firearm to be registered accordingly.

How to Measure Overall Length:The overall length of your rifle or shotgun may also classify it as a Short Barrel Rifle or Short Barrel Shotgun. The overall length of a firearm is the distance between the muzzle of the barrel and the rearmost portion of the weapon measured on a line parallel to the axis of the bore. … If the rifle has a permanently attached muzzle device, that is part of the overall length. … If the rifle or shotgun has a collapsible stock, the overall length is measured with the stock extended.

READ FULL ARTICLE on Ammoland.com.

Links for this episode:

ATF Method for Measuring Barrel Length and Overall Length:
https://www.atf.gov/firearms/docs/atf-national-firearms-act-handbook-chapter-2/download
Firearm – 26 USC § 5845: https://www.law.cornell.edu/uscode/text/26/5845
Firearm – 27 CFR § 479.11: https://www.law.cornell.edu/cfr/text/27/479.11
Short Barrel Rifle – 18 USC § 921(a)(8): https://www.law.cornell.edu/uscode/text/18/921
Short Barrel Rifle – 27 CFR § 478.11: https://www.law.cornell.edu/cfr/text/27/478.11
Short Barrel Shotgun – 18 USC § 921(a)(6): https://www.law.cornell.edu/uscode/text/18/921
Short Barrel Shotgun – 27 CFR § 478.11: https://www.law.cornell.edu/cfr/text/27/478.11

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