Short answer
No factory builds a true clone of Blancpain's Calibre 1315. The replica 5050-1130-52A movements you find in listings are decorated Asian automatics. Most are ETA 2824 clones such as the Seagull ST2130 or the Hangzhou 6460. The cheaper ones are 21,600 vph workhorses dressed up with a Blancpain-engraved rotor and decorative bridge plates. They keep time. They do not have three mainspring barrels, they do not run 120 hours, and they are not 1315s.
What the real watch carries
Calibre 1315 is a large automatic: 30.6 mm across, 5.85 mm tall, 227 components, 35 jewels. Three mainspring barrels sit in series to pull a 120-hour reserve at 28,800 vph. Add a silicon balance spring, a free-sprung balance with gold timing screws, and hand finishing that includes cotes de Geneve on the bridges, anglage on the edges, and perlage under the rotor. That last part matters here, because replica makers can copy the look of the finishing. They cannot copy what makes the finishing possible.
The three tiers you will actually be offered
- Cheap tier. A DG2813 or Mingzhu automatic at 21,600 vph. The sweep looks choppy, the rotor is loud, and the reserve lands under 40 hours. Often sold as a "Swiss movement" with no proof behind the claim.
- Mid tier. Seagull ST2130 or Hangzhou 6460, both built on 2824 architecture, 28,800 vph, roughly 38 hours of reserve. Sellers call it a "clone 1315" once a decorative plate and a Blancpain rotor are fitted. It still has one barrel.
- Top tier. A custom-decorated Asian automatic with Geneva stripes, blued screws, a jewel count stamped to match the real spec, and a rotor engraved with the Blancpain wordmark. This is the best you will find. It is also the one most often misrepresented.
How to check what is inside before you pay
- Ask for a clear, well-lit photo of the movement with the caseback off. If the seller only has stock images, that tells you something.
- Count the mainspring barrels. The 1315 layout shows three. One barrel sitting under a wide bridge means a 2824 family movement wearing a costume.
- Confirm the beat rate. 28,800 vph is the floor for anything worth buying at this price. 21,600 is a tell.
- Wind it fully, set it down, and check it at 48 hours. A real 1315 runs well past 100. A replica will be stopped.
- Listen to the rotor. A slow wobble with a light rattle is normal on a 2824 clone. A grinding scrape is not.
- Check engraving depth. Genuine Blancpain engraving is crisp and cut. Most replica rotors are laser-etched, so the letters look shallow and slightly frosted.
Why the "1:1 movement" claim is marketing
Tooling for a three-barrel in-house caliber only pays off at volume, and a 1315 clone would sell in the low thousands, not the hundreds of thousands. So the reps use movements that already exist and then dress them. That is an honest tradeoff as long as the seller states it plainly. The trouble starts when "swiss clone 1315, 120 hour reserve" shows up in a listing, because that combination does not exist at replica prices.
What to ask a seller
Base movement name and factory. Beat rate. Measured power reserve, not the claimed one. Whether the rotor and bridges are decorative or functional. Whether the watch was timed on a machine, and the numbers. A seller who answers all six is worth dealing with. A seller who answers with "best quality, super clone" is not.
Ownership reality
Service is the weak point. A 2824 clone can be swapped or repaired by almost any watchmaker for small money. A heavily decorated top-tier movement is harder, because the cosmetic plates come off and go back on, and the parts are not catalogued. If you plan to wear the watch daily, take the version with the proven base caliber. Budget for a service every few years, and do not expect a repair shop to source genuine 1315 parts for it.
Bottom line: buy the case, dial, and bezel you like, but judge the replica by the base movement inside, not by the "1315" engraving on the rotor.