Maxim Defense Tumble Upon Impact TUI Short Barrel 556x45mm NATO Rifle Ammo 70 Grain Solid Copper Spun SCS 25 Rounds per Box MXM 49002 UPC 680017490027
Product Description
The Maxim Defense® Tumble Upon Impact® (TUI®) 5.56x45mm NATO 70 Grain Rifle Ammunition (SKU: MXM-49002 / UPC: 680017490027) is a match-grade, lead-free Short Barrel Ammunition (SBA) load packaged at 25 rounds per box. Engineered specifically to overcome the velocity-dependent terminal limitations of sub-10-inch AR-15 pistols, PDWs, and SBRs—such as the Maxim Defense PDX and MDX platforms—this cartridge delivers uncompromising barrier penetration, surgical accuracy, and decisive terminal trauma for personal defense, law enforcement duty, and tactical applications.
Built around a patented, CNC-lathed 70-grain Solid Copper Spun (SCS®) monolithic projectile developed in partnership with Fort Scott Munitions®, this round eliminates the need for high-velocity fragmentation to create wide wound channels. Unlike conventional hollow-point or open-tip bullets that can clog with drywall, auto glass, or heavy clothing and fail to expand at lower short-barrel velocities, the solid copper TUI® projectile retains 100% of its mass through hard barriers and immediately initiates violent end-over-end yawing upon entering soft tissue. Delivering 2,874 fps muzzle velocity and 1,284 ft-lbs of energy in standard 24-inch test data while maintaining devastating cavitation cycles out of 5.5-inch to 16-inch barrels, it bridges the gap between compact weapon portability and full-power rifle lethality.
Each cartridge is assembled using virgin, reloadable brass cases charged with clean-burning, flash-suppressed propellant tailored for rapid pressure curve completion inside short gas systems. Maxim Defense® utilizes non-corrosive, military-grade hard Boxer primers engineered to withstand the floating firing pin impulse of AR-15/M4 bolt carrier groups, preventing slam-fires during chambering while guaranteeing positive ignition in adverse environmental conditions. Because the projectile is 100% solid copper with zero lead core, it is also fully compliant for indoor ranges and lead-restricted training or hunting jurisdictions.
*Master Ballistician Bench Notes & Range Staging Guidance:*
Chamber Compatibility & Pressure Advisory: Loaded to full 5.56x45mm NATO operating pressure. Compatible exclusively with firearms clearly marked 5.56 NATO or .223 Wylde featuring a 1:7" or 1:8" barrel twist rate required to gyroscopically stabilize the extended-length 70-grain monolithic copper projectile. CRITICAL WARNING: Do NOT fire 5.56x45mm NATO ammunition in rifles stamped strictly ".223 Remington" due to shorter SAAMI throat leade and higher NATO chamber pressures. Slower 1:9" or 1:12" twist barrels may fail to stabilize 70-grain solid copper bullets, causing keyholing or baffle strikes if fired through a suppressor. Always segregate 5.56 NATO magazines from .300 AAC Blackout ammunition.
- Verify the firearm chamber stamping and barrel markings match the exact 5.56x45mm NATO cartridge designation printed on the ammunition headstamp and box prior to loading.
- Inspect individual cartridges during magazine staging for seated primer uniformity, brass case wall integrity, and consistent overall cartridge length (COAL) free of bullet setback.
- When staging for short-barreled rifles (5.5" to 10.5") or suppressed hosts, verify proper bolt lock-back on an empty magazine and inspect suppressor alignment before live-fire deployment.
- Confirm dedicated zero and point-of-impact (POI) shift at your primary engagement distance, as heavy 70-grain monolithic copper projectiles will track differently than standard 55-grain M193 or 62-grain M855 training loads.
- Store remaining ammunition in a cool, dry, climate-controlled environment (ideally inside a sealed M2A1/M19A1 ammo can with desiccant packs) and observe strict Ground hazardous materials shipping and handling regulations.
Key Features
- 70-Grain Solid Copper Spun (SCS®) TUI® Projectile: CNC-machined monolithic lead-free copper bullet engineered to retain 100% weight, defeat intermediate barriers, and tumble upon impact for massive hydrostatic cavitation even at short-barrel velocities.
- Short Barrel Ammunition (SBA) Ballistic Optimization: Calibrated propellant burn curve maximizes velocity, minimizes muzzle flash, and ensures reliable cycling in compact 5.5" to 11.5" AR-15 pistols and SBRs.
- Military-Grade Hard Boxer Primers & Virgin Brass: Reloadable brass casings fitted with thickened mil-spec primer cups eliminate slam-fire risk in free-floating AR-15 firing pin systems.
- 100% Lead-Free & Range Compliant: Non-toxic monolithic copper construction satisfies lead-free indoor range mandates and state environmental hunting regulations without sacrificing terminal authority.
- 25-Round Tactical Box Packaging: High-density 25-round retail box format (625 rounds per 25-box case) provides convenient magazine-fill staging for duty, home defense, and precision testing.
Product Specifications
- Brand: Maxim Defense Industries®
- Series / Load Line: Tumble Upon Impact® (TUI®) Short Barrel Ammunition (SBA)
- MPN / SKU: MXM-49002 / MXM49002
- UPC: 680017490027
- Caliber / Gauge: 5.56x45mm NATO
- Grain Weight: 70 Grain (4.54 g)
- Bullet / Projectile Type: Solid Copper Spun (SCS®) Tumble Upon Impact® (TUI®) Monolithic Spitzer
- Muzzle Velocity: 2,874 fps (24" Test Barrel)
- Muzzle Energy: 1,284 ft-lbs (24" Test Barrel)
- Casing Material: Virgin Reloadable Brass
- Primer Type: Boxer, Non-Corrosive, Military-Grade Hard Cup
- Reloadable: Yes
- Corrosive: No
- Quantity / Round Count: 25 Rounds per Box
- Country of Origin: United States
