Introduction to Reloading Metal Cartridges: Walkthrough


DISCLAIMER: All technical data in this publication, particularly for hand loading, reflects the limited experience of persons using specific tools, products, equipment and components under specific conditions and circumstances which are not necessarily stated. in the article and over which the National Rifle Association (NRA) has no control. The data has not been otherwise tested or verified by the NRA. The NRA, its officers, officers and employees accept no responsibility for the results obtained by persons using this data and accept no liability for any consequential injury or damage.

From the safe: part two of our introduction to reloading metal cartridges. As published in the May 2001 issue of Shooting Sport United States. (Read part one here.)

Introduction to Reloading Metal Cartridges Part II

Navigate the charging process
By Stanton L. Wormley, Jr.

In this second installment on reloading metal cartridges, we will follow the sequence of steps involved in reloading a shotgun shell and refining a metal cartridge charge. These steps are based on the use of a single-stage reloading press and a separate priming tool.

Before you start crafting your own ammo, make sure all of your components and reload data are up to date. Component specifications and reloading data may vary over the years due to changes in component specifications and safety standards. Using old components with recent data – or vice versa – is problematic. Additionally, some components such as powders can deteriorate over time, especially if they have been stored in areas of high heat or humidity.

It is also important to ensure that any components you plan to use match the published reload data. Few things are more frustrating than sitting down to reload and discovering that none of your reloading manuals list a load that uses the components you have on hand. You may give in to the dangerous temptation to substitute a bullet, type of primer, or brand of case for that listed in the manual. Avoid this dangerous pitfall by ensuring you have the correct components before starting a reload session.

Step 1

Clean, inspect and sort crates. Clean cases first, as flaws such as cracks in the mouth or case body show up best on clean, shiny cases. After cleaning, inspect the cases individually for such defects. During this process, it is easy to sort the crates by manufacturer and place them in loading blocks to create batches of 50 or 100 crates.

2nd step

Select the appropriate shell holder and place it on the cylinder. Most reloading manuals contain tables showing the correct shell carrier for a given cartridge.

Step 3

Mount and adjust the calibration die in the press. Normally the sizing die is screwed into the press until it just touches the shell carrier when the ram is at maximum height (or just away from contact when carbide dies are used). You must adjust the decapping pin to fully squeeze out the spent primer without the expander ball touching the case canvas. All new dies come with instructions on how to use them.

Step 4

Lubricate the housings. Case lubricant (available in solid, liquid or spray form) prevents cases from getting stuck in the die and decreases the effort required to operate the press. With a bottleneck holster, the lubricant is applied only to the body of the holster, not the shoulder. Case lubricant is not required with carbide or titanium nitride coated dies.

Step 5

Resize and depress the case. Running the case completely lubricated in a properly fitted die will resize the case to its original dimensions and remove the worn primer. Additionally, the resized case neck is restored to the proper inside diameter when the expander ball is removed from the case. After resizing, remove any remaining lubricant from the housings.

Step 6

Measure the length of the casing. Shooting and resizing can stretch the cases, so it is necessary to measure each case with a caliper or case length gauge to ensure it is within the proper limits. A case that is too long may not be accommodated. Additionally, the mouth of a case that is too long can be inadvertently pinched inward by the shoulder of the case mouth in the chamber, resulting in a potentially dangerous pressure build-up.

Step 7

Cut the cases. Use the box cutter to cut excessively long cases down to the “cut to” length listed in the reloading manual; follow the instructions that come with the mower.

Step 8

Deburr and chamfer the housing mouth. Use a chamfering tool to remove any burrs or rough edges from the inside and outside edges of the case mouth. Also, a slightly chamfered or beveled mouthpiece will make it easier to seat the ball.

Step 9

Clean the primer pocket. When primer residue and other material accumulates in the primer pocket, primer seating becomes uneven, primer firing becomes erratic, and charging performance suffers. Primer pocket cleaners remove these residues. Inspect the flash hole for burrs or obstructions. Military cases reloaded for the first time must have the crimp removed before accepting a new primer.

Step 10

Prime the case. Place each primer with even pressure to the bottom of the primer pocket. Moderate resistance should be felt when the primer is in place. Make sure that the primer in place does not protrude above the level of the housing head.

Step 11

Measure the powder charge. Use a reloading scale to weigh the powder charge for each case. An alternative is to use a powder doser to quickly dose the appropriate load by turning a crank. Since the charges emitted from a measure of powder can vary somewhat, a measure should never be used for maximum charges. Launching consistent powder loads using a measure depends on the consistent operation of the measure opening handle. Also, when using a measure, check the charge it throws every five to 10 turns. NEVER exceed the maximum powder load listed in the reloading data.

Step 12

Check the powder charge. Once you have filled all the cases in the batch with powder, visually check that each case has the correct amount of powder. With all filled crates upright in the loading block, the crate light is angled into the crate vents. Any variation in powder loading will be readily apparent. Alternatively, you can use a depth gauge, such as a marked piece of dowel, to check each case’s powder level.

Step 13

Place the ball. The seat matrix must first be adjusted. Unscrew the bullet seat post several turns and thread the die into the press just far enough that the mouth of an empty case just contacts the crimp shoulder in the die. Then back the die out a quarter turn and lock it in place. Then, with the seat post still back and an empty case still in the shell mount, insert a bullet of the appropriate type into the mouth of the case and feed the case through the seat die. Resistance will be felt as the die begins to push the bullet into the case neck. Initially, the ball will protrude excessively from the neck. Screw in the seat post a little at a time and continue to run the case through the die, measuring the overall cartridge length (OAL) each time with a vernier caliper until the proper length is reached . If a crimp is needed, back off the seat post approximately one turn, screw the seat die body in until the crimp shoulder produces the proper amount of crimp in the case mouth, then readjust the seat post for the appropriate OAL cartridge.

A good seat depth is essential. Too much bullet protrudes and the cartridge may not work through the gun magazine, or it may not seat. Too little and the bullet enters the powder chamber excessively, decreasing the volume and increasing the pressure. Neck tension is also important; any bullet that fails to seat with some resistance can only be held loosely by the neck and can be pushed back into the case when the cartridge is chambered, especially in semi-automatic weapons.

Step 14

Identify refilled cartridges. For security reasons and for general record keeping, you must label each box of refilled cartridges you manufacture. The label should contain full details of the charge, the number of times the cases were cut and refilled, the total length of the cartridge and the date the refills were made.

Test and tune the load

After you’ve mastered the basic technique of assembling safe and functional loads, you’ll probably want to fine-tune your loads to improve accuracy, trajectory, and terminal performance.

As your test loads approach this “perfect” load, the groups get tighter. Once you have established that the best accuracy is obtained with, say, between 40 and 41 grains of powder X, you can load an additional series of test cartridges having finer powder load increments (such as 40.0 , 40.2, 40.4, 40.6, 40.8 and 41.0 grains of Powder X). Careful record keeping is essential for proper analysis of test firing results.

Signs of high pressure in metal canisters

Above: The reloader should be able to recognize signs of high pressure, such as (A) a soot ring of gas escaping around the primer, (B) an enlarged primer pocket with spots of leaking gas, leaving the primer loose, (C) an open primer pocket, which releases the primer, (D) flattening of the primer, (E) cratering of the primer, caused by the pressure extrusion of primer cup material into firing pin hole, (F) perforation or rupture of primer, (G) flow of brass into recesses of extractor or ejector, (H) engraving of breech marks on the case head and (I) expansion of the case head.

Secure storage of ammunition and components
  • Still store reloading components in their original factory containers.
  • Still store reloading components away from heat, moisture and exposure to open flames.
  • Be extremely cautious and alert when dealing with live bait. Careless handling that ignites one primer can detonate others nearby.
  • Never store powder and primers in one place.
  • Store recharge components where children and unauthorized persons cannot access them.

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