300 AAC Blackout, 125 Gr Maker T-REX (Tipped Rapid EXpanding) – 20 Rounds

300 AAC Blackout 125gr Maker T-REX – Supersonic Hunting Ammunition

The Just Cause Solutions 300 AAC Blackout 125gr Maker T-REX is a purpose-built supersonic hunting load designed to maximize the terminal potential of the 300 Blackout platform. Featuring Maker's Tipped Rapid EXpanding solid copper projectile, this load delivers reliable expansion and deep penetration on medium game — making it a serious option for hunters and shooters running 300 Blackout in AR-platform rifles or bolt guns. At 2,200fps from a 16" barrel, it hits hard and expands decisively.

All of our ammunition is pressure tested using a PCB PIEZOTRONICS Conformal Transducer according to Voluntary Industry Performance Standard as set forth by SAAMI.

Technical Specifications

Barrel Length & Velocity Data

The Maker T-REX Advantage

The T-REX builds on Maker's proven REX expanding copper platform by adding a polymer tip for improved ballistic coefficient and more consistent long-range performance. Key features include:

• Polymer tip – Increases BC for a flatter trajectory and improved wind resistance at distance
• Reliable expansion – Engineered to expand consistently across a wide velocity range
• Nearly 100% weight retention – Solid copper construction maintains mass for deep penetration
• CNC-machined precision – Every projectile is machined to exact tolerances for consistent performance
• Lead-free construction – Compliant with lead-free hunting regulations where applicable

Hunting Application

The 300 AAC Blackout has become a go-to cartridge for hunters who want AR-platform compatibility without sacrificing terminal performance on medium game. The 125gr T-REX takes full advantage of the cartridge's supersonic capability, delivering a hard-hitting, expanding copper projectile well-suited for whitetail deer, hogs, and similarly sized game at appropriate ranges. The T-REX's expanding copper construction delivers a wide wound channel with deep penetration — without the lead core separation concerns of traditional bonded bullets.

It is the hunter's responsibility to adequately test their rifle system at distance prior to hunting wild game!

Frequently Asked Questions

Q: What game is this load appropriate for?
A: The 125gr T-REX in 300 Blackout is well-suited for medium game including whitetail deer, hogs, and black bear at appropriate ranges. Shot placement and distance remain the hunter's responsibility.

Q: Will this reliably cycle a standard 300 Blackout AR?
A: Yes. This is a supersonic load and will cycle standard 300 Blackout AR-platform rifles reliably. As always, we recommend testing function in your specific rifle before field use.

Q: What makes the T-REX different from the standard REX?
A: The T-REX adds a polymer tip to Maker's proven REX design. This improves the ballistic coefficient for a flatter trajectory and more consistent expansion initiation on impact, particularly at longer ranges where velocity has decreased.

Q: Can I use this in a suppressed 300 Blackout?
A: Yes. This supersonic load pairs well with a suppressor to reduce muzzle blast. Keep in mind a supersonic crack will still be present downrange. For a fully suppressed, hearing-safe experience, a subsonic load would be required.

Q: What twist rate does my barrel need?
A: A 1:8 or faster twist rate is recommended to properly stabilize the 125gr T-REX projectile. Most modern 300 Blackout barrels are manufactured with a 1:8 twist, which is ideal for this load.

Q: How is Just Cause USA's ammunition tested?
A: Every batch we produce is pressure tested using our own PCB PIEZOTRONICS Conformal Transducer according to Voluntary Industry Performance Standard as set forth by SAAMI. This level of in-house testing is uncommon in the industry and reflects our commitment to safety and consistency in every round we release.