Hublot’s Big Bang 301.SM.1770.RX at 44mm represents this replica big bang 1770 44mm in the steel chronograph segment that made the collection famous. The reference number places it within the original Big Bang family tree, using a stainless steel case paired with a black dial and rubber-integrated deployment system. At 44mm across, the case diameter matches the standard proportion that defined early Big Bang releases before the line expanded into 39mm and 45mm variants. The 1770 designation in the reference points to a specific dial and material configuration within the broader 301 series.

Case & Movement Specs

• Reference: 301.SM.1770.RX
• Case diameter: 44mm
• Case material: stainless steel
• Bezel: six H-shaped titanium screws on steel
• Dial: black with luminous markers
• Crystal: sapphire flat with AR coating
• Movement: automatic chronograph
• Functions: hours, minutes, small seconds, chronograph, date

The six exposed screws on the bezel remain one of the most recognizable design elements in modern watchmaking. Each screw uses an H-shape that echoes the brand logo, doubling as both structural fastener and visual signature across every Big Bang reference.

Caliber Breakdown

The automatic chronograph inside runs a familiar architecture with column wheel or cam-lever switching depending on the specific caliber variant. Date sits at the four-thirty window, and the chronograph registers cover 30-minute and 12-hour totalizers alongside a running seconds subdial. The power reserve hovers around 42 hours on a full wind. Within the steel Big Bang range, the 301.PX.130.RX in gold shares the same 44mm case architecture but shifts the material palette dramatically. Both are accessible through the Big Bang collection page.

How It Compares

Against ceramic-bezel variants like the 301.SB series, this full-steel 1770 reference leans more traditional. The absence of ceramic means a uniform metallic surface that catches light differently, reflecting rather than absorbing. That makes it slightly more versatile for formal settings where an all-black watch might feel too casual. The 44mm hublot big bang steel chronograph format remains the backbone of the collection, and this replica big bang 1770 44mm sits right at the center of that foundation.