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December 28th, 2024

Saturday Movies: Building a AR-15 Black Rifle Start to Finish

Cheaper Than Dirt AR-15 AR AR15 building assembly video page

Cheaper Than Dirt (CTD), a Texas-based vendor of firearms, gun accessories, and ammo, has created a very complete web page on AR-15 assembly from start to finish. If you are thinking of building an AR, or upgrading your upper, trigger group, or buttstock, we recommend that you read CTD’s DIY ARs — Building Your Own AR-15 page. This illustrates all the components you will need for a complete AR build.

In addition, the page has a series of videos showing how to assemble each element of the AR-15. We’ve included five of those videos in today’s Saturday Movie Showcase. There a total of ten CTD AR-15 videos in the series. View them all on the CTD AR-15 Playlist on YouTube.

Then, as a closer, we offer another video — the Ten Mistakes to Avoid When Building an AR-15. Worth watching BEFORE you start an AR project, this useful video now has 2.6 million views!

Installing the Fire Control Group

Installing the Safety Selector and Pistol Grip

Installing the Take-Down Pin and Buffer Tube

Installing the Bolt Catch

Field-Stripping the Bolt-Carrier Group

Mistakes to Avoid When Assembling an AR-Platform Rifle
This popular Tactical Toolbox video (with 2.6 million views) is definitely worth watching BEFORE you start your own AR project. It explains the common mistakes that even careful builders can make when assembling an AR-type rifle.

The 27 Parts Needed for Do-It-Yourself ARs

Here’s a helpful CTD infographic that shows the parts needed to build an AR-15. These parts are available for purchase at Cheaper than Dirt. To learn more, click the photo to view the full CTD AR-15 Build article.

Cheaper Than Dirt AR-15 AR AR15 building assembly video page


Top photo with AR upper kit and stripped lower from Palmetto State Armory.

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December 28th, 2024

Access 60+ Authoritative Sierra Ballistics Articles for FREE

Sierra Bullets Ballistics Resources

Need some informative reading material for winter days? Here’s a vast resource available free from Sierra Bullets. Here are links to over 60 articles with information on bullets, ballistic coefficients, wind drift, up/down angles, temperature effects, tailwind effects and much more. Most of these resources come from the respected Sierra Reloading Manuals, 4th and 5th Editions. There are enough articles to read one per week for a year!

Major Ballistics Reference Articles
The Ballistic Coefficient by William T. McDonald & Ted C. Almgren (Adobe .PDF)
Deflections and Drift of a Bullet in a Crosswind by William T. McDonald (Adobe .PDF)
Inclined Fire by William T. McDonald

Table of Exterior Ballistic Coefficients
(5th Edition Reloading Manual)

Rifle
Handgun
.22 Rimfire

Exterior Ballistic Tables
(4th Edition Reloading Manual)

Rifle Tables – Select by Bullet
Handgun Tables – Select by Bullet
Silhouette Tables – Select by Bullet

5th Edition Manual Exterior Ballistics Section
Section 1.0 Introduction
Section 2-2.1 The Ballistic Coefficient Explained
Section 2.2 Bigger Is Not Always Better
Section 2.3 How the Ballistic Coefficient is Measured
Section 2.3.1.1 Measurement Procedure
Section 2.3.1.2 Important Precautions and Points to Consider
Section 2.3.2 Initial Velocity and Time of Flight Method
Section 2.3.3 Doppler Radar Method
Section 2.4 Lessons Learned from Ballistic Coefficient Testing
Section 2.5 Examples of Ballistic Coefficient Measurements
Section 3.0 Exterior Ballistic Effects on Bullet Flight
Section 3.1 Effects of Altitude and Atmospheric Conditions
Section 3.2 Effects of Wind
Section 3.3 Effects of Shooting Uphill or Downhill
Section 3.4-3.4.1 Trajectory Considerations for Sighting in a Gun
Section 3.4.2 Determining Zero Range from Firing Test Results
Section 3.4.3 Sighting in for a Change in Shooting Location
Section 3.5 Point Blank Range
Section 3.6 Maximum Horizontal Range of a Gun
Section 3.7 Maximum Height of Fire of a Gun
Section 4.0 Six Degree of Freedom Effects on Bullet Flight
Section 4.1 Basic Physical Concepts
Section 4.2 Yaw of Repose and Resulting Crossrange Deflection
Section 4.3 Turning of a Bullet to Follow a Crosswind and Resulting Deflections
Section 4.4 Turning of a Bullet to Follow a Vertical Wind and Resulting Deflections
Section 5.0 Trajectory Tables
Section 6.0 Sierra’s Infinity Exterior Ballistics Software

4th Edition Manual Exterior Ballistics Section
Section 2.0 Introduction
Section 3.0 Historical Summary
Section 4.0 The Ballistic Coefficient
Section 4.1 Basic Definitions
Section 4.2 Ballistic Coefficients Effects on Bullet Trajectories
Section 4.3 How the Ballistic Coefficient is Measured by Firing Tests
Section 4.4 Lessons Learned From Ballistic Coefficient Measurements
Section 4.5 Ballistic Coefficient Variations with Muzzle Velocity near the Speed of Sound
Section 4.6 Ballistic Coefficient Dependence on Coning Motion
Section 5.0 Exterior Ballistics Topics
Section 5.1 Effects of Altitude and Atmospheric Conditions
Section 5.2 Effects of Altitude and Uphill/Downhill Shooting
Section 5.3 Wind Effects
Section 5.3.1 Headwinds and Tailwinds
Section 5.3.2 Crosswinds
Section 5.3.3 Winds from Any Direction
Section 5.4 Changing the Zero Range
Section 5.5 Point Blank Range
Section 5.6 Muzzle Velocity Dependence on Cartridge Temperature
Section 6.0 Equations of Bullet Flight
Section 6.1 Differential Equations of Bullet Motion
Section 6.2 Drag Force and the Drag Function
Section 6.3/Section 6.3.1 Siacci’s Method/The Change of Independent Variables
Section 6.3.2 The Assumption
Section 6.4 Mayevski’s Analytical Form of the Drag Model
Section 6.5 Closed-Form Solutions for Trajectory Parameters
Section 6.6 Other Useful Equations
Section 6.6.1 References

Sierra Bullets Ballistics Resources

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December 28th, 2024

Guide to Loading Cases with Auto-Indexing Progressive Presses

USAMU Progressive Press auto  self-advancing

The U.S. Army Marksmanship Unit regularly publishes reloading “how-to” articles on the USAMU Facebook page. One very good article, part 5 of a 6-part series, focused on Progressive Presses. This article explains proper procedures for Auto-Indexing Progressives, which advance the shell-plate with every pull of the handle. Auto Progressives are very efficient, but they also require special attention and focus, because so many things are happening at once. You need to train yourself to watch every station. If you run a progressive press now, or are considering getting a progressive, we recommend you read this article. Visit the USAMU Facebook page for other helpful handloading guidance.

Progressive Loading Presses — Self-Advancing Shellplate Type

USAMU Progressive Press auto  self-advancing
Photo courtesy UltimateReloader.com.

Recently, we addressed manually-operated progressive presses for the beginning handloader. This type press requires one to manually advance the shellplate after each handle stroke. An advantage for beginners is that nothing happens at any station until the loader wants it to. This helps users avoid problems from clearing malfunctions without noticing that the shellplate has advanced itself. (Read Previous USAMU Article on Manual Progressives.)

The next, more luxurious type progressive press advances the shellplate automatically whenever the handle is cycled. [Editor: This is also called an “Auto-Indexing” Progressive Press.] Typically, each stroke automatically sizes and primes a case, operates the powder measure (if used) and seats a bullet. Some also have case feeders that automatically put a new case in the shellplate with every cycle. Others require the loader to insert a case each cycle. With both types, the loader usually puts a bullet on each sized/primed/charged case.

[CAVEAT: While our Handloading Shop has several progressive presses, ALL of our powder charges are thrown/weighed by hand. We do not use powder measures on our presses. Our progressives are used for brass preparation, priming, seating, etc., but not for fully-progressive loading.]

The manually-advanced press can be a boon to beginners, but as one gains experience it can be a mixed blessing, depending on one’s style. If one pays close attention to every operation and loads without distractions, the manual press is very reliable and allows full scrutiny of each round as it is loaded. However, if one easily drifts into day-dreaming, or isn’t focused on paying careful attention at all times, the manual progressive can be a bit of a liability. The opportunity for forgetting a powder charge, leading to a squib load, is ever-present. [Editor: A lock-out die can help reduce the risk of a squib load, or a double-charge. See below.]

The automatically-advancing progressives help prevent this by ensuring a powder charge will be dropped each time the handle is operated. Experienced handloaders often appreciate this feature due to the savings of time and effort. Individual preferences between the two press styles are influenced by several factors. These include one’s comfort with more- vs. less-complicated mechanisms, how often one changes calibers (case feeders often must be converted, in addition to dies and shellplates), how many rounds one loads annually, relative ease of changing primer mechanisms from small to large, etc. Automatic progressives and their caliber conversion kits tend to be significantly more expensive than manual progressives and caliber conversions from the same maker.

One USAMU handloader, who likes simple, bullet-proof machines and maximum efficiency when converting presses, owns two manually-advanced progressives. One is set up for large primers, and the other for small primers. He can change calibers in the twinkling of an eye. As he loads for many different calibers, this fits his style. Another handloader here is just the opposite. He loads for a few calibers, but in larger quantities. He much prefers his self-advancing press with case-feeder for its speed. He makes large lots of ammo in a given caliber before switching, to improve overall efficiency. His caliber conversion kits are more expensive than those for the manually-advanced progressive, but he uses fewer of them.

Whichever type one chooses, it is VERY important to buy quality gear from a manufacturer with a long, well-established track record for quality, durability and good customer support. Avoid jumping on the “latest, greatest” model until it has a proven track record. For example, this writer knows a loader who got a brand-new, expensive, self-advancing model press some years back, shortly after its introduction. As is too often the case these days, the manufacturer released it before all the “bugs” were worked out.

Better Safe Than Sorry — the RCBS Lock-Out Die
RCBS Makes a “Lock-Out Die” that senses the powder charge. This will halt the Progressive press if you have a double charge, or an undercharge. Your Editor has the Lock-Out Die on his RCBS Pro 2000. It has “saved his bacon” a half-dozen times over the years. It can be used on Dillon and Hornady progressives as well as RCBS machines.

It would not fully seat primers to the correct depth. No amount of adjustment, extra force, or fiddling would do better than to seat primers barely flush with the case head. Any inattention could result in a slightly “high” primer, protruding above the case head. It created a risk for slam-fires, particularly in semi-autos without spring-retracted firing pins, such as the M1 or M1A. In desperation, he had a machinist buddy study the problem and machine a new part to correct it. No dice. Its engineering didn’t permit full primer seating, even with extended parts. He now wishes he’d heeded his shooting buddies’ advice to stick with the “tried and true,” reliable performer they all used.

Whichever press one selects, see if the maker has a kit or list of commonly-replaced parts. Having needed springs, pins, etc. on hand in the rare event that one breaks or “goes missing” can save the day when one is busy loading for a match! Another tip for improving one’s overall loading efficiency (rounds loaded with minimal set-up/tear-down time) is to plan one’s handloading by primer size. For example, if your machine is set to use small primers, load all the calibers that you intend to that take small primers, before converting the press to load large-primer calibers.

In our next chapter, we’ll discuss peculiarities of progressive loading for rifle cartridges, with remedies for problems such as excessive cartridge-case headspace variation when sizing, tips for ensuring best powder charge consistency, and so on. Until then, be safe, and good shooting!

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