I just purchased an S & W model 686 + Performance Center sku 11760. The website does not say if it has EDM or broach cut rifling. The dealer didn't know either. Anybody know?

First, it's ECM rifling, not EDM. As to whether yours is ECM or broach cut, you may be able to tell with a visual inspection. Broach cut rifling has very "square" corners in the transitions from lands to grooves. ECM has a more rounded transition and it's sometimes mistaken for polygonal rifling.

Adios,

Pizza Bob

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