
Availability: In Stock
The Sinclair International Expander Die Body 17-338 Caliber is a precision reloading tool designed for serious handloaders working with large-caliber magnum and wildcat cartridges. Built from stainless steel and engineered as part of Sinclair's Generation II expander die system, this die body accepts Sinclair's large-caliber mandrels to prepare case necks for consistent, accurate neck turning. If you're pushing the limits of rifle precision—whether you're chasing sub-MOA groups on the range, handloading for a magnum hunter, or developing wildcat rounds—proper case neck preparation is non-negotiable, and this die is built to deliver the consistency that counts.
The 17-338 die body uses an O-ring design that allows the mandrel to float slightly and self-center within the case neck, capturing the mandrel fully so it won't pull loose during use. This keeps your setup stable across multiple firings and resizing cycles. The die threads are 7/8"-14, the standard for large-caliber reloading equipment, and it ships with a Sinclair Stainless Steel Split Lock Ring included. While the die body itself is a workhorse, remember that expander mandrels are sold separately—you'll need to source the correct mandrel for your specific caliber to complete your setup.
Sinclair expander dies serve multiple roles in the handloading workflow: they're essential for neck-turning accuracy, they can restore dinged or bruised case necks, they help establish uniform bullet tension across a lot, and they're invaluable for "necking up" brass when developing wildcat loads one caliber step at a time. For precision rifle shooters who refuse to accept mediocre case prep, the 17-338 expander die body is a foundation tool.
| Manufacturer | Sinclair International |
| Product Type | Expander Die Body |
| Caliber | 17-338 |
| Material | Stainless Steel |
| Thread Size | 7/8"-14 |
| Generation | II |
| Included Accessories | Split Lock Ring (Stainless Steel) |
| Mandrel | Sold separately |
Mandrels for this die body are sold separately. You'll need to select the appropriate large-caliber mandrel from Sinclair for your specific application. Refer to Sinclair's mandrel lineup to find the correct match for your 17-338 setup.
The 17-338 die body uses a 7/8"-14 thread, which is the standard thread size for large-caliber reloading equipment. It will fit any press or reloading station designed to accept 7/8"-14 dies.
The Generation II design fully captures the mandrel within the die body so it cannot pull out during use. An O-ring allows the mandrel to float slightly, enabling it to self-center within the case neck for more consistent results across multiple reloading cycles.
Yes. Sinclair expander dies are commonly used for "necking up" brass one caliber step at a time when developing wildcat loads, in addition to their primary role in neck-turning workflows.

SKU: 197558773 • Weight: 0.35oz





Availability: In Stock
The Sinclair International Expander Die Body 17-338 Caliber is a precision reloading tool designed for serious handloaders working with large-caliber magnum and wildcat cartridges. Built from stainless steel and engineered as part of Sinclair's Generation II expander die system, this die body accepts Sinclair's large-caliber mandrels to prepare case necks for consistent, accurate neck turning. If you're pushing the limits of rifle precision—whether you're chasing sub-MOA groups on the range, handloading for a magnum hunter, or developing wildcat rounds—proper case neck preparation is non-negotiable, and this die is built to deliver the consistency that counts.
The 17-338 die body uses an O-ring design that allows the mandrel to float slightly and self-center within the case neck, capturing the mandrel fully so it won't pull loose during use. This keeps your setup stable across multiple firings and resizing cycles. The die threads are 7/8"-14, the standard for large-caliber reloading equipment, and it ships with a Sinclair Stainless Steel Split Lock Ring included. While the die body itself is a workhorse, remember that expander mandrels are sold separately—you'll need to source the correct mandrel for your specific caliber to complete your setup.
Sinclair expander dies serve multiple roles in the handloading workflow: they're essential for neck-turning accuracy, they can restore dinged or bruised case necks, they help establish uniform bullet tension across a lot, and they're invaluable for "necking up" brass when developing wildcat loads one caliber step at a time. For precision rifle shooters who refuse to accept mediocre case prep, the 17-338 expander die body is a foundation tool.
| Manufacturer | Sinclair International |
| Product Type | Expander Die Body |
| Caliber | 17-338 |
| Material | Stainless Steel |
| Thread Size | 7/8"-14 |
| Generation | II |
| Included Accessories | Split Lock Ring (Stainless Steel) |
| Mandrel | Sold separately |
Mandrels for this die body are sold separately. You'll need to select the appropriate large-caliber mandrel from Sinclair for your specific application. Refer to Sinclair's mandrel lineup to find the correct match for your 17-338 setup.
The 17-338 die body uses a 7/8"-14 thread, which is the standard thread size for large-caliber reloading equipment. It will fit any press or reloading station designed to accept 7/8"-14 dies.
The Generation II design fully captures the mandrel within the die body so it cannot pull out during use. An O-ring allows the mandrel to float slightly, enabling it to self-center within the case neck for more consistent results across multiple reloading cycles.
Yes. Sinclair expander dies are commonly used for "necking up" brass one caliber step at a time when developing wildcat loads, in addition to their primary role in neck-turning workflows.
SKU: 197558773 • Weight: 0.35oz
