.223 / 5.56mm Once-Fired Reloading Brass for Sale

How We Process .223 Remington / 5.56 NATO Brass

Our .223 Remington / 5.56 NATO brass passes through multiple stages of mechanical sorting, cleaning, inspection, and quality control before being packaged for sale.

Incoming brass is first processed to remove steel cases, aluminum cases, rimfire cases, and other unwanted materials. It is then sorted using a combination of specialized equipment designed to separate cases by material, body diameter, rim diameter, and case length. Depending on the product selected, additional cleaning or sorting steps may be performed.

Washed & Polished brass is cleaned using our industrial wet-cleaning process and then dried and polished in heated corncob media to improve its appearance while helping preserve the brass during storage.

Every batch is then hand-inspected to remove cases showing split necks, severe corrosion, major physical damage, severely damaged rims, excessive discoloration, or other conditions that could affect reloadability.

Our Quality Standard

Once-fired brass is a previously used product, and every case has its own history. While no inspection process can identify every possible defect, our goal is to provide brass that we would be confident using ourselves.

Many inspection decisions rely on practical reloading experience rather than a simple checklist. If a case does not meet the quality standard we expect for our own reloading bench, we would rather remove it than ship it.

Regardless of where your brass is purchased, every reloader should thoroughly inspect every case before reloading. This is one of the most important steps in producing safe, reliable ammunition. While we work hard to identify and remove defective cases, once-fired brass is a previously used product and no inspection process can guarantee that every defect will be found. The final inspection should always be performed by the individual assembling the ammunition.

Most once-fired brass orders include approximately 2–3% additional brass. While this helps compensate for the occasional case that may not meet our quality standards or your individual expectations, it should never replace a careful inspection before loading.

For additional information about once-fired brass, inspection, primer crimps, flash holes, safety considerations, and our overpack policy, please visit our Brass Information page.

.223 Remington Quick Specifications

The following information provides a practical reference for commonly checked .223 Remington cartridge and case dimensions. Always consult current published reloading data and official standards before loading ammunition.

Official SAAMI Reference

For complete cartridge and chamber drawings, dimensional tolerances, and pressure standards, consult the official SAAMI specifications.

View Official SAAMI .223 Remington Specifications

Preparing .223 Remington / 5.56 NATO Brass for Reloading

Proper case preparation is an important part of producing safe, reliable, and consistent rifle ammunition. Every case should be inspected, resized, measured, and prepared according to current published reloading data before loading.

Military Primer-Pocket Crimps

Many military 5.56x45mm NATO cases contain circular or staked primer-pocket crimps. A primer crimp is a normal manufacturing feature intended to help secure the primer and is not considered a defect.

After the spent primer is removed, the crimp generally must be swaged or reamed before a replacement primer can be seated properly. Unless the individual product description specifically states otherwise, customers should expect to perform any required primer-pocket preparation.

Case Length and Trimming

.223 Remington and 5.56 NATO brass can lengthen during firing and resizing. Cases should normally be measured after resizing and trimmed as necessary to remain within the specifications provided by current published reloading data.

A commonly used trim-to length for .223 Remington is approximately 1.750 inches, while the SAAMI maximum case length is 1.760 inches.

Commercial and Military Brass

Commercial .223 Remington brass and military 5.56 NATO brass share similar external dimensions, but internal capacity, case-wall thickness, hardness, and primer-pocket construction may vary by manufacturer and headstamp.

Whenever changing manufacturers, headstamps, or military and commercial case types, begin with published starting loads and work up carefully. Do not assume that the same powder charge will produce identical results in every case.

Headstamp Sorting

Our standard .223 Remington / 5.56 NATO brass is sold as mixed headstamp unless otherwise specified. Mixed-headstamp brass is commonly used for training, recreational shooting, and general-purpose ammunition.

Reloaders seeking greater consistency may choose to sort cases by manufacturer, headstamp, case weight, or production lot before loading.

Case Life

The useful life of .223 Remington and 5.56 NATO brass depends on factors including chamber dimensions, load pressure, resizing practices, firearm type, and the condition of the individual case.

Every case should be inspected before each loading. Cases showing cracks, severe corrosion, excessive deformation, signs of incipient case-head separation, or other questionable conditions should be discarded.

Annealing

Some reloaders choose to anneal bottleneck rifle brass as part of their long-term case-maintenance routine. Annealing is intended to restore ductility to the neck and shoulder area after repeated firing and resizing and may help maintain more consistent neck tension over multiple loading cycles.

Annealing is optional and is most commonly practiced by precision rifle shooters or reloaders seeking greater consistency over extended case life. Many reloaders produce reliable ammunition throughout the normal service life of their brass without annealing.

Anyone choosing to anneal cartridge cases should follow accepted procedures and use equipment designed for that purpose. US Reloading Supply does not currently offer annealing services.

NAS3 Cases

NAS3 cases use a specialty multi-piece construction and should not be processed as conventional one-piece cartridge brass. They require the tools and procedures specified by the case manufacturer.

When NAS3 cases are offered by USRS, they are listed as a separate product option and clearly identified in the product title and Short Description.

For additional information about primer crimps, flash holes, case variations, processing options, and inspection practices, please visit our Brass Information page.

About the .223 Remington Cartridge

Introduced in the 1960s, the .223 Remington has become one of the most popular centerfire rifle cartridges in North America. Its mild recoil, excellent accuracy, and broad selection of bullet weights have made it a favorite among recreational shooters, hunters, competitive shooters, and reloaders alike.

The closely related 5.56x45mm NATO cartridge shares nearly identical external dimensions and is widely used by military and law enforcement organizations around the world.

.223 Remington vs. 5.56x45mm NATO

Although .223 Remington and 5.56x45mm NATO cartridges share very similar external dimensions, they are not always interchangeable. Differences in chamber dimensions and loaded-ammunition specifications can affect operating pressures.

Firearms chambered specifically for 5.56 NATO will generally fire both 5.56 NATO and .223 Remington ammunition. However, firearms marked only for .223 Remington should generally not be fired with 5.56 NATO ammunition unless the firearm manufacturer specifically states that it is safe to do so.

Always follow the firearm manufacturer's recommendations and use current published load data when selecting ammunition or developing reloads.

Common Firearms Chambered in .223 Remington

.223 Remington is commonly used in:

• AR-15 style rifles
• Bolt-action hunting rifles
• Single-shot rifles
• Varmint and predator rifles
• Competition rifles
• Numerous sporting rifle platforms

Commercial and Military Brass

Our standard .223 Remington brass is sold as mixed headstamp unless otherwise specified. Depending on the source of each batch, customers may receive commercial and occasional military headstamps.

Lake City brass is separated and offered as its own product option whenever practical. Military brass commonly contains primer-pocket crimps and may differ slightly from commercial brass in case construction and internal capacity.

Nickel-Plated Brass

Nickel-plated .223 Remington brass is occasionally available as a separate product option. Many reloaders appreciate nickel-plated cases for their corrosion resistance, distinctive appearance, and ease of identification.

NAS3 Cases

NAS3 cases use a unique two-piece construction that differs from traditional one-piece brass cartridge cases. Whenever available, NAS3 cases are sold separately and clearly identified so they are not confused with conventional brass.

Seconds Brass

When available, Seconds brass is sold separately from our standard inventory. These cases may exhibit cosmetic discoloration, stains, dents, scratches, or other non-critical imperfections. Customers should review the individual product description to understand the specific condition being offered.

For additional cartridge history, technical articles, and educational resources, visit our Reloading Knowledge Center as new content becomes available.

Frequently Asked Questions About .223 Remington / 5.56 NATO Brass

Q: Is this .223 brass deprimed?
A: No, unless specifically stated otherwise in the individual product title or Short Description.

Q: Is this brass Boxer primed?
A: Yes. Our standard .223 Remington brass is Boxer primed unless the individual product title or description states otherwise.

Q: Is this mixed-headstamp brass?
A: Yes. Our standard .223 Remington / 5.56 NATO brass is sold as mixed headstamp unless otherwise specified.

Q: Is military brass included?
A: Depending on the product selected and the composition of the batch, military headstamps may be present. Military cases commonly contain primer-pocket crimps that require additional preparation before reloading.

Q: Do you separate Lake City brass?
A: Yes. Lake City brass is separated and sold as its own product option whenever practical.

Q: What is the difference between .223 Remington and 5.56 NATO brass?
A: Although the cases share nearly identical external dimensions, military 5.56 NATO brass may differ from commercial .223 Remington brass in case construction, internal capacity, hardness, and primer-pocket configuration. Reloaders should always begin with published starting loads whenever changing manufacturers or case types.

Q: Can I reload 5.56 NATO brass using .223 Remington dies?
A: Yes. Standard .223 Remington reloading dies are commonly used to process Boxer-primed 5.56 NATO brass. Military primer crimps typically must be removed before seating a new primer.

Q: What is a primer crimp?
A: A primer crimp is a manufacturing feature commonly found on military cartridge cases to help retain the primer. It is not considered a defect, but it usually must be removed before a new primer can be seated.

Q: Does .223 brass need to be trimmed?
A: Yes. .223 Remington and 5.56 NATO brass generally lengthen during firing and resizing. Cases should be measured after resizing and trimmed as necessary to remain within published specifications.

Q: Can I reload nickel-plated .223 brass?
A: Yes. Nickel-plated .223 Remington cases can generally be reloaded using the same procedures as standard brass cases, provided they pass inspection.

Q: What are NAS3 cases?
A: NAS3 cases use a specialized two-piece construction and require different handling than conventional one-piece brass cases. Whenever available, NAS3 cases are sold separately and clearly identified.

Q: What is Seconds brass?
A: Seconds brass consists of cases with cosmetic imperfections such as discoloration, stains, dents, or scratches that do not meet our standard cosmetic grading. Customers should review the individual product description for the specific condition being offered.

Q: Why do you include extra brass?
A: Most once-fired brass orders include approximately 2–3% additional brass. Once-fired brass is a previously used product, and while we work hard to maintain high quality standards, no inspection process is perfect. We also recognize that every reloader's inspection standards and intended use may differ. Please see our Brass Information page for details regarding our overpack policy.

Q: Should I inspect every case before reloading?
A: Yes. Every case should be thoroughly inspected before loading, regardless of whether the brass is new, once-fired, or previously reloaded. The final inspection is always the responsibility of the individual assembling the ammunition.

Q: Where can I learn more about once-fired brass?
A: Visit our Brass Information page for additional information about inspection, primer crimps, flash holes, case preparation, safety, and our overpack policy.