What level of bullet neck tension does the Redding 21545 mandrel provide for standard .30-caliber loads?

The Redding 21545 features a precision-ground diameter of 0.3060 inches, which is engineered specifically to deliver a consistent 0.0020-inch neck tension or interference fit when loading standard 0.308-inch diameter projectiles like the .308 Winchester and .300 Win Mag. Accounting for typical brass spring-back, this uniform inside neck sizing helps lower velocity standard deviations and improve long-range group sizes.

What equipment is required to set up and operate this expanding mandrel on my reloading bench?

This mandrel must be installed inside a Redding Precision Expanding Die Body, which mounts into any standard 7/8"-14 threaded reloading press commonly used across Australian workshops. Prior to running cases over the 0.3060" mandrel, ensure your case neck inside diameter has been pre-sized smaller than this dimension. Additionally, applying a quality case neck lube such as Redding Imperial Sizing Die Wax ensures smooth operation and prevents brass pickup.

Are there any Australian electrical or regulatory compliance standards that apply to this reloading component?

No, the Redding 21545 expanding mandrel is an entirely mechanical tool steel accessory requiring zero electricity. Therefore, it is exempt from Australian 240V electrical requirements, SAA approvals, and RCM regulatory compliance markings.

How should I maintain the hardened tool steel mandrel for long-term use in outback environments?

Constructed from CNC-machined and precision-ground tool steel, the mandrel is designed for durability on indoor reloading benches. To protect it from humidity and environmental moisture common in coastal or outback Australian regions, wipe the part down with a light coat of rust-preventative gun oil or preservative after use and store it in a dry location.

Redding 21545 Mandrel - Redding 21545

The Redding Precision Expanding Mandrel 0.3060 (MPN 21545) is a hardened, CNC-machined, and precision-ground tool steel reloading component designed to expand cartridge case necks from the inside. Built for standard .30-caliber cartridges firing nominal 0.308-inch diameter projectiles—such as the .308 Winchester, .30-06 Springfield, .300 Win Mag, .300 PRC, and .300 AAC Blackout—this mandrel eliminates internal neck wall thickness variations and smooths imperfections following resizing. It utilizes proprietary angled alignment surfaces on its base to seat squarely within a Redding Precision Expanding Die Body, preventing mandrel tilt and reducing total cartridge runout.

Key Features

Precision Inside Neck Sizing: Expands brass from the interior outward to establish consistent interference fit across case lots.
Axial Alignment Surfaces: Machined with proprietary angled base geometry to eliminate runout when installed in a Redding Precision Expanding Die Body.
Hardened Tool Steel Construction: Precision-ground for smooth operation, durability, and resistance to wear during high-volume reloading.
Laser-Marked Identification: Features the .3060 diameter clearly marked on the top face for fast visual confirmation on the reloading bench.

Product Specifications

Manufacturer: Redding Reloading Equipment
Part Number (MPN): 21545
Material: Hardened, CNC-machined, precision-ground tool steel
Mandrel Diameter: 0.3060 inches
Calibre Family: .30 Caliber (0.308-inch projectile diameter)
Die Interface: Sized for Redding Precision Expanding Die bodies (requires standard 7/8"-14 press threading)
Power Requirements: None (manual mechanical operation)

Who is the Redding 0.3060 Expanding Mandrel for?

Precision long-range handloaders loading .30-caliber cartridges — relies on the exact 0.3060-inch mandrel diameter to expand .30-calibre brass and correct internal neck wall thickness inconsistencies after bushing or full-length sizing.
Handloaders aiming to lower velocity standard deviations through precise neck tension control — utilizes this expanding mandrel to establish a uniform 0.0020-inch neck tension interference fit on standard 0.308-inch projectiles, providing consistent bullet release pressures.

Less suitable for: Applications where the case neck inside diameter is already expanded to 0.3060 inches or larger prior to sizing, or for handloaders requiring heavy neck tension (0.0025 to 0.0030 inches) or light neck tension (0.0010 to 0.0015 inches), which require alternative stepped mandrels sized at 0.3055/0.3050 inches or 0.3065/0.3070 inches respectively.

SKU	RD41488LP
Model #	21545
Brand	Redding
Shipping Weight	1.0000kg

What our Customers are Saying

We Also Recommend

Sellier & Bellot 300 Winchester Magnum Unprimed Br

$57.95

Kleenbore Cp16b Cotton Cleaning Patches 1.25 Inch

$32.95

Recommended Products

Redding 21523 Expanding Mandrel 0.2625 In 6.5mm Re

$80.95

Redding 21527 Precision Expanding Die 6.5mm 0.2630

$169.95

Redding 21541 Precision Expanding Die 7mm 0.2830 M

$169.95

Redding 21544 Expanding Mandrel 308 Cal 03065 Tool

$80.95

Welcome to Xhunter Australia. By accessing and using our website (www.xhunter.com.au) and purchasing from our online store, you agree to be bound by the following Terms and Conditions. Please read them carefully before proceeding.

1. Eligibility

By agreeing to these Terms and Conditions, you confirm that:

• You are at least 18 years of age.
• You are legally capable of entering into a binding contract under Australian law.
• You will not purchase any restricted or controlled items unless legally permitted to do so.

2. Product Information

• All products listed are subject to availability.
• Product descriptions, specifications, and pricing are subject to change without notice.
• We make every effort to display products accurately, although we do not guarantee that all images or content are error-free.

3. Orders and Payments

• All orders are subject to acceptance and confirmation.
• Prices are in AUD and include GST unless otherwise stated.
• We reserve the right to cancel or refuse any order at our sole discretion.
• Full payment is required before dispatch.

4. Authority to Leave (ATL) and Delivery

• By default, all orders are shipped with Authority to Leave (ATL).
• If you require Signature on Delivery, please contact us prior to purchasing. Additional charges apply.
• If an order is returned to us due to failed delivery or non-receipt when ATL is not permitted, a $25 return processing fee must be paid before reshipment or refund.

5. Returns and Refunds

• Please refer to our full Returns Policy on the website.
• Returned items must be in original, resalable condition unless faulty.
• A restocking fee may apply if an item is not in reselling condition.
• Change-of-mind returns may not be accepted for clearance or custom-ordered items.

6. Firearms and Restricted Items

• You must comply with all relevant State and Federal laws for regulated products.
• You are responsible for ensuring proper licences and permits are held.
• We reserve the right to request proof of eligibility before dispatch.

7. Limitation of Liability

• Xhunter Australia is not liable for direct or indirect losses arising from the use or misuse of products.
• We are not responsible for any unauthorised modifications or incorrect application of products.

8. Manufacturer Warranty Support

Some products sold by Xhunter Australia include a manufacturer’s warranty (for example, limited lifetime warranties). These warranties are provided solely by the manufacturer and are separate from the consumer guarantees under Australian Consumer Law.

Where a manufacturer provides a warranty:

A. The warranty is offered and honoured by the manufacturer, not by Xhunter Australia, unless expressly stated otherwise.
B. Customers may be required to contact the manufacturer directly and comply with their warranty process, which may include overseas product assessment.
C. Proof of purchase is required to lodge a manufacturer warranty claim.
D. Assistance provided by Xhunter Australia in lodging warranty claims is a goodwill service only and does not imply liability for warranty outcomes or decisions.

Nothing in this clause limits your rights under Australian Consumer Law.
Xhunter Australia remains responsible for providing legally required remedies for products that fail to meet the consumer guarantees of acceptable quality, fitness for purpose, and reasonable durability.

9. Privacy

Your personal information is collected, used, and stored in accordance with our Privacy Policy.

10. Intellectual Property

All text, graphics, logos, and images on this website remain the property of Xhunter Australia and are protected by copyright laws.

11. Amendments

We may update or modify these Terms and Conditions at any time without prior notice. Continued use of our site constitutes acceptance of any updated Terms.

12. Governing Law

These Terms and Conditions are governed by the laws of Victoria, Australia. Any disputes will be handled exclusively by the courts of Victoria.

13. 18+ Age Requirement

By placing an order, you confirm that you are at least 18 years of age and legally entitled to purchase the products ordered. We may cancel any order that breaches this requirement.

Redding 21545 Expanding Mandrel 30 Caliber 0.3060 Tool Steel

Secure Payment Methods