What exact diameter is the Hornady 391930 mandrel and what calibre is it designed for?

The Hornady 391930 mandrel features a precision diameter of 0.336 inches (~8.53 mm) and is strictly constrained to .338 calibre rifle cases. It is engineered specifically to support popular long-range and ELR cartridges such as the .338 Lapua Magnum, .338 Norma Magnum, and .338 Winchester Magnum during neck turning operations.

Will this mandrel fit third-party neck turning tools from brands like Sinclair or PMA?

No, this mandrel is exclusively engineered to screw directly into the Hornady Lock-N-Load Neck Turn Tool chassis. It does not fit third-party neck turning tools without custom modifications, so you should ensure you are using the correct matching tool body.

Do I need any special preparation for my .338 brass before using this turning mandrel?

Yes, cases must be properly resized, neck-expanded (ideally using an expander mandrel about 0.0007 inches larger than the turning mandrel), deburred, and inside-neck lubricated prior to turning. This crucial preparation prevents friction galling, binding, and inconsistent wall thickness removal.

Are there any Australian electrical compliance or safety certifications required for this tool?

As the Hornady 391930 is a purely mechanical reloading component with no electrical parts or power requirements, mains power ratings, Australian plugs, and SAA or RCM electrical compliance certifications are not applicable. It can be freely purchased and used across Australia without firearms licensing restrictions.

How do I prevent heat build-up and maintain tight tolerances during extensive reloading sessions?

To prevent thermal expansion of the stainless steel mandrel during heavy batch processing in your reloading room, you should use low tool or drill RPM alongside light cutting passes of 0.001 to 0.002 inches per pass. Keeping the brass properly lubricated will also eliminate friction-induced heat build-up.

338 Neck Turning Mandrel - Hornady 391930

The Hornady Neck Turning Tool Mandrel .338 Caliber (MPN: 391930) is a dedicated reloading accessory designed to support the interior case neck during turning operations. Machined from stainless steel with a silver finish, this mechanical tool threads directly into the Hornady Lock-N-Load Neck Turn Tool frame. It maintains a precise mandrel diameter of 0.336 in (approximately 8.53 mm) to ensure a close slip fit inside expanded .338-calibre cartridge necks, allowing the cutter to remove high spots and achieve uniform wall thickness for reduced bullet runout.

Key Features

Internal Neck Support: Sized to an exact 0.336 in (8.53 mm) diameter to support the inside surface of .338-calibre cases during the turning cut.
Precision Wall Uniformity: Removes neck wall thickness variations to establish concentric bullet seating across match-grade brass.
Shoulder Stop Integration: Features an integrated shoulder stop setting that prevents the neck turning cutter from making contact with the case shoulder.
Durable Stainless Construction: Precision-machined from solid stainless steel to resist wear during repeated case preparation cycles.

Specifications

Brand: Hornady
Model / MPN: 391930
Calibre Compatibility: .338 calibre (8.6 mm)
Mandrel Diameter: 0.336 in / ~8.53 mm (nominal distributor target ~0.3355 in)
Material: Stainless steel
Packaged Dimensions: 50.8 × 19.1 × 95.3 mm (2.0 × 0.75 × 3.75 in)
Packaged Weight: Approximately 45 g (0.1 lb)
Tool Compatibility: Hornady Lock-N-Load Neck Turn Tool

Who is the Hornady 391930 Neck Turning Tool Mandrel For 338 Caliber Reloading for?

Long-range and ELR reloaders — seeking consistent neck tension and reduced runout on large-capacity .338 Lapua Magnum or .338 Norma Magnum cases will benefit from this neck turning mandrel's precision 0.336 in (8.53 mm) diameter, which provides the rigid internal support necessary to turn down high spots to an exact wall thickness.
Precision benchrest shooters — preparing uniform .338 Winchester Magnum or .338 Edge brass require this 45 g stainless steel neck turning tool mandrel to establish strict neck concentricity while preventing the cutting blade from encroaching past the neck-shoulder junction.

Less suitable for: Cartridge cases outside of .338 calibre (such as .30 cal, 7mm, or .375 cal cases), which require dedicated smaller or larger calibre-specific neck turning mandrels, or reloaders using third-party neck turning chassis that require brand-specific proprietary mandrel threads.

SKU	HN102588LP
Model #	391930
Brand	Hornady
Shipping Weight	0.0200kg

What our Customers are Saying

We Also Recommend

Lee Breech Lock Challenger Kit Iii - With Auto Be

$414.95

Sellier & Bellot 300 Winchester Magnum Unprimed Br

$57.95

A-zoom Precision 357 Magnum Metal Snap Caps Solid

$53.95

Grovtec Gtsw07 Machine Screw Fore End Swivel Set 1

$26.95

Recommended Products

Lee Precision 90137 30-40 Krag Case Length Gauge A

$27.95

Rcbs Trim Pro 3 Way Case Trimmer Pilot Chamfer Rel

$35.95

Lyman Brass Smith Case Trim Xpress Bushing Ly-Bsx2

$37.95

Rcbs R90419 Case Neck Turner Pilot 36 Cal Hardened

$49.95

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.

Hornady 391930 Neck Turning Mandrel 338 Caliber Stainless Steel

Secure Payment Methods