You sound very sure. Good, how about Actual proof? Every person actual involved in the movie said there were two 6.5" 29's. The only people pushing the .41 Mag theory are people at gun shops trying to get folks to buy a Model 57, "it's the gun they Really used in a Dirty Harry"....yea, right. I love the .41 Mag. First revolver I owned was a full house Magna Port Model 57 Predator package in the mid 80's. Nobody wished Dirty Harry's .44 was really a 57.......but I can't find anyone actually involved in the movie or the Hollywood weapons community (where I have worked and spent a lot of time with) have offered up anything other than the two 29's.

So.....think its a 57, prove it. Research it, find the serial numbers, the receipts from the prop house (which are very detailed with serial numbers and descriptions...cause it is a very regulated business with very well defined paper trails), the Armorer who prepped the guns, the property master who ordered or had the .41 Mag blanks built. Believe me, a .44 mag converted to .45 Colt would have been a far more believable story as blank operation is a big issue.

Good luck and looking forward to something other than speculation.

Just saw your link. Read this again, it is from your own link-keyword-misconception.

"The actual gun used on set by Clint Eastwood was in fact a Smith & Wesson Model 29. It is a common misconception that a Model 29 could not be located and a Model 57, chambered in .41 Magnum, was used instead. Clint Eastwood contacted Bob Sauer, representative for Smith and Wesson, to acquire the pistol. The Model 29 had been out of production for several years at the time, but a number of pistols were assembled from parts at the factory and provided to the crew. Eastwood took one to a firing range to familiarize himself with the Model 29."