The top pick for a replica Speedmaster cal 863 is a hand-wound three-register copy in a 42 mm case with a solid, era-correct caseback and a domed crystal, because register layout and movement type are the two things that decide whether the watch reads as a Moonwatch or as a generic chronograph wearing a famous dial. The criteria used here: register count and placement, movement type and winding feel, case and pusher geometry, bezel and dial printing, crystal material, and how the case sits on an average wrist.

What Cal 863 Means and Why It Shapes the Copy

Cal 863 sits in the Lemania 1873 family. It is commonly described as a hand-wound, cam-switched chronograph with 17 jewels and a rhodium-plated finish, used in Speedmaster Professional production from the early 1980s into the 1990s, before Omega applied the 1861 label to the same rhodium-finished architecture. Two practical points follow from that.

First, the layout is fixed: running seconds at 9, a 30-minute counter at 3, and a 12-hour counter at 6. A two-register movement cannot fake that. It gives you seconds at 9 and minutes at 3, and the missing register at 6 is visible from arm's length. Second, the original Moonwatch in this era shipped with a solid steel caseback, so a display back is a deviation. It reveals the movement, which is the reason some buyers want it, but it is not the correct configuration for the period.

Option One: Hand-Wound Three-Register Copy (Top Pick)

This is the version that gets the dial architecture right. Expect a 42 mm case, roughly 20 mm lugs, a domed crystal with a slight warm distortion, and pushers set at the correct height and angle.

Pros

  • Three registers at 3, 6, and 9, so the dial proportions match the reference
  • Hand winding gives the same daily ritual as the original movement family
  • Era-correct solid caseback hides whatever movement finishing falls short
  • Sweeping chronograph hand with a mechanical reset snap

Cons

  • Costs more than automatic and quartz copies
  • You have to wind it, and forgetting means a dead watch
  • A display back version exposes rough finishing that a solid back would conceal
  • Fewer sellers carry this configuration, so stock is uneven

Use it if you want the closest visual match and you are willing to wind a watch each morning. It works best as a rotation piece rather than a beater.

Option Two: Automatic Copies and Reduced-Style Cases

Automatic versions usually borrow the smaller 39 mm Speedmaster Reduced silhouette or a generic three-register layout built around an automatic chronograph.

Pros

  • Wear-and-forget convenience, no winding needed
  • Lower price than a hand-wound mechanical
  • Smaller case suits wrists under about 6.5 inches
  • Often stocked with a date window for daily use

Cons

  • Subdial sizes and spacing rarely match the Professional dial
  • Thicker mid-case and flatter pusher feel
  • Date windows and crown guards break the vintage read
  • Rotor noise and wobble on cheaper movements

Use it if this is your only chronograph and you want a daily wearer that never needs winding. Accept that the dial geometry is an approximation.

Option Three: Quartz Copies

Pros

  • Cheapest entry point and the easiest to replace
  • Accurate timekeeping with almost no maintenance
  • Light on the wrist and thin under a cuff

Cons

  • Ticking seconds hand is an instant giveaway
  • Subdials are frequently decorative rather than functional
  • Chronograph pushers feel hollow and reset without snap
  • Case finishing is usually the weakest of the three tiers

Use it if you want the silhouette for occasional wear and do not care about the chronograph working correctly.

Buyer Checklist Before You Order

  1. Count the registers and confirm positions at 3, 6, and 9.
  2. Confirm the movement is mechanical and winding is required.
  3. Check the bezel: a 1980s and 1990s style should show the dot beside the 70 rather than the earlier dot over 90.
  4. Look at the crystal: a domed profile suits this reference better than a flat sapphire.
  5. Measure the lugs: 20 mm keeps strap options open.
  6. Ask for a photo of the caseback engraving and the pusher side profile.

Fit and Daily Wear

At 42 mm with 20 mm lugs, this case wears wider than the number suggests because the lugs are straight rather than curved. On a 7 inch wrist it lands well on a leather strap; on a 6.5 inch wrist it will overhang slightly. If that describes you, the smaller automatic option is the better call, and the cal 863 story becomes a detail you cannot fully use.