Lee Precision 300 Rem Ultra Mag Rifle Prec Micrometer Bullet Seat Die

The Lee Precision 300 Rem Ultra Mag Rifle Precision Micrometer Bullet Seat Die brings repeatable, user-friendly accuracy to your reloading bench without the premium price tag. Built for reloaders who demand consistent seating depth across cartridge runs, this die combines a laser-engraved micrometer adjustment system with Lee's floating bullet guide design — proven in testing to deliver minimal bullet runout and tight tolerance control.

If you're loading for a 300 Rem Ultra Mag and tired of guessing at seating depth or fighting with finicky adjustment mechanisms, this die offers a straightforward solution. The micrometer thimble reads in thousandths of an inch, just like a precision depth gauge, so you can dial in your exact seating length and replicate it shot after shot. The floating bullet guide keeps the case and bullet in perfect alignment during seating, and the hardened, burnished stem glides over virtually any bullet point style without scuffing or deformation.

A standout feature for handloaders: the bullet guide is reversible and can be repositioned to allow simultaneous seating and crimping — a capability exclusive to Lee among value-oriented die manufacturers. This flexibility saves time if your load development or production schedule calls for combined operations. Whether you're fine-tuning precision rifle ammunition for long-range hunting, competition, or target work, the micrometer adjustment and dead-length seating contact give you the control to dial in exactly what your rifle demands.

Key Features

• Laser-engraved micrometer thimble with 0.001" divisions for precise, repeatable seating depth adjustment
• Dead-length seating design ensures uniform cartridge dimensions from round to round
• Floating bullet guide with radial clearance for perfect case-to-bullet alignment and minimal runout
• Hardened, burnished bullet seating stem that seats virtually any bullet point style without marking or damage
• Reversible floating guide allows simultaneous seating and crimping when needed
• Designed for 300 Rem Ultra Mag rifle cartridges

Specifications

Frequently Asked Questions

Will this die work with my 300 Rem Ultra Mag press setup?

Yes — the Lee Precision 300 Rem Ultra Mag Rifle Precision Micrometer Bullet Seat Die is designed specifically for the 300 Rem Ultra Mag cartridge and is compatible with any standard single-stage or progressive reloading press that accepts standard die threads.

Can I use this die for both seating and crimping?

The bullet guide is reversible, so you can reposition it to allow simultaneous seating and crimping in a single stroke — an exclusive feature to Lee dies in this price range. If you prefer to seat and crimp separately, you can use it in standard seating-only mode.

How do I adjust the seating depth with the micrometer?

The micrometer thimble is laser-engraved with divisions representing 0.001" of an inch, and it reads just like a precision depth micrometer. Dial your desired seating depth, and the die will repeatedly seat bullets to that exact specification. The dead-length design ensures the shell holder contact confirms uniform seating across all your cartridges.

Will this die mark or damage bullets during seating?

The bullet seating stem is machined and burnished specifically to seat virtually any bullet point style without marking or deformation, so you can load hollow-points, boat-tails, or soft-nose bullets with confidence.