What color is titanium DLC and how does it compare to the black barrel? The picture appears to be a gloss black. — 1 Answer

Titanium DLC has a more glossy, satin black appearance whereas black nitride is more matte, satin dark gray/black.

DLC is a hard, low‑friction carbon coating, notable for its very low friction and excellent wear resistance in sliding contacts. The coating achieves a very high coating hardness that can reach ~1,000–3,000 HV in many formulations; often higher than nitride. Excellent abrasion resistance. Due to its application process, DLC adds a measurable coating thickness (~0.5–5 µm) which can affect tight fits/threads.

Nitride/QPQ is a thermochemical diffusion process that hardens and darkens the steel itself. It too has excellent corrosion resistance, good wear resistance, very durable adhesion (because it’s part of the substrate), and minimal dimensional change. It is often considered the best practical choice for threaded or tight‑tolerance barrel bores and for long‑term corrosion protection.