Not the OP, but someone
knew that this firearm was on-set
knew what rounds fit this firearm
and knew where to purchase those rounds
That's quite a knowledge base.
BTW Academy Sports NE, just over a half hour south in Albuquerque shows .45 rounds in stock. Don't know if these are suitable for this revolver. (Wonder if CCTV was checked?)
Big 5, well, imho their website needs an upgrade, might or might not have .45 in stock in Santa Fe or ALB.
Didn't try Wal-Mart's website, 2 locations in Santa Fe, but seriously it would be easier to run to ALB unless you needed something else.
Now one may need a New Mexico driver's license to purchase these, last time I bought ammo in NM I had a New Mexico license.
Remember that ammunition isn't handled in the mail -- the PO asks you every time you mail a package, remember?
Redundantly, someone knew that revolver, and had that round.
Does that sound like a professional armorer's knowledge???
jmho ymmv lrr