PDI 6.01mm precision barrels are made of cold hammer forged SUS304 stainless steel. They are among the highest quality barrels available for airsoft. They are made in Japan with extremely tight bore tolerances of +- 0.002mm.
For TM VSR-10.
Inner Diameter: 6.01mm
Outer Diameter: 8.55mm
Made of cold hammer forged SUS304 Steel