EXPERT SUMMARY
About Ultra Defense Corp 5.56x45mm M193 55gr FMJ
UDC 5.56x45mm 55gr M193 is loaded to full military specification by a company that fills ammunition contracts for the US Government. Every major component — powder, primer, projectile, and case — comes from a top-tier US defense supplier, the same names found in US military ammunition. Assembled to M193 spec with premium US-sourced parts throughout, this is not budget-tier surplus or a commercial import. If you run an AR-15 or other 5.56/.223-chambered rifle and want mil-spec quality range and training ammo from a genuine government contract loader, this load delivers real pedigree.
Performance
Loaded to M193 specification, this 55gr FMJ drives a nominal 3,240 fps from a 20-inch barrel, delivering the flat trajectory and reliable function that made M193 the benchmark 5.56 training and general-purpose load. St. Marks propellant burns clean and consistent for predictable velocity and confident, repeatable shot placement across strings of fire.
Reliability
General Dynamics brass, CCI primers, and mil-spec projectiles are assembled under military-grade tolerances and QC standards by a contract loader for the US Government. The result is dependable feeding, extraction, and ignition in AR-15 platforms, and consistent cycling in both carbine- and rifle-length gas systems. UDC's ISO 9001:2015 facility holds production to the same discipline applied to its military contract runs.
Expansion Characteristics
As a full metal jacket projectile, M193 is not designed to expand. Its terminal behavior comes from velocity-dependent yaw and fragmentation: at sufficient impact speed the bullet yaws and can fragment at the cannelure, which is the mechanism behind M193's well-documented terminal effect. This is standard FMJ behavior and makes the load ideal for training, practice, and general range use rather than controlled-expansion defensive work.
Recoil Characteristics
At 55 grains and standard M193 velocity, felt recoil is light and flat-shooting — the mild, easily managed impulse that makes 5.56 such a fast-follow-up, high-volume training cartridge. Most shooters describe it as a soft push, ideal for extended range sessions and drill work.
Terminal Performance
M193 terminal performance is governed by impact velocity: above roughly 2,500 fps the projectile is prone to yaw and fragmentation, tapering to a simpler through-and-through at longer ranges as velocity drops. This is the classic, predictable behavior of the M193 specification — the reason it has served as a general-purpose 5.56 load for decades.
Ultra Defense Corp 5.56x45mm 55gr M193 — Lot Test Summary
To view the complete Lot Test Summary report, click here.
About Ultra Defense Corp
Ultra Defense Corp (UDC) is an American-owned small business established in 2010 and headquartered in Tampa Bay, Florida. It operates an ISO 9001:2015 certified facility and is registered with the US Department of State and Department of Justice as an importer, exporter, and manufacturer of defense articles.
A prime contractor for the US Government, SOCOM, and allied nations, UDC has been awarded dozens of contracts exceeding $500 million — including positions on the US Army's $490M SAWS multi-award IDIQ and the $750M SOCOM Unique Munitions Requirement (SUMR) small-caliber contract. UDC is one of the sole manufacturers of the 40mm M781 chalk round for US Military and Law Enforcement, operates three federally licensed facilities producing small, medium, and large caliber ammunition, and has been recognized by multiple US Government agencies for quality control, regulatory compliance, and OPSEC. The same operation building for US and allied militaries produces this ammunition.
