UDMC produces its barrels from cylindrical blanks supplied by Dikar S. Coop BERGARA of Spain whom UDMC represents as distributor in the entire Asia-Pacific Region. The Bergara cylindrical blanks are made from the finest carbon steel and stainless steel, used in the ordnance, aerospace and defence industries. If other suppliers will say that their barrels are SS-416, only a Certificate of Chemical Analysis can determine its quality. UDMC’s AISI 416 Stainless Steel PREMIUM ordnance grade barrel has contents of Vanadium, Nickel and Molybdenum which are not found in a standard AISI 416 stainless steel barrel. The net effect is that the United Defense - Bergara barrels have a yield strength of 780 MPa (versus 275 MPa of std AISI-416 SS) and a tensile strength of 920 MPa (versus 517 MPa of std AISI-416 SS). In terms of toughness, UDMC barrel is 73 Joules versus 34 Joules of the std AISI-416 SS.
The optimum combination of high hardness, yield strength, and tensile strength, along with the correct toughness, allow UDMC barrels to withstand the generated pressures when the rifle is in battery, even with powerful rounds such as the .30 caliber or the .50 caliber precision rifles.
UDMC barrels, compared with other stainless steel barrels in the firearms industry, are very hard steel which increases the mechanical properties of the barrels and it is fair to say that this is one of the best insurances from the safety point of view of a barrel. In addition to this, one of the differences of UDMC barrels is the small grain size of its molecular structure thus guaranteeing excellent toughness. The homogenous microstructure during hardening and tempering provides a uniform hardness along the bar, producing a very uniform rifled bore, which is the key to accuracy of a barrel. The heat treatment, in combination with the precise deep hole drilling, honing and button rifling process results in a uniform finish of the bore under 0.0008 inches. The stress relieving heat treatment on the other hand, after the button rifling process, protects the bore from inside deformation after the tapering of the barrel. It also helps protect the barrel from heat generated after continuously firing several hundreds of rounds.
Finally, the high chromium content of UDMC barrels provides a good corrosion resistance to it.