Very interesting thread! I have a few notes about barrel length. I have six S&W .44 mags, N frame. I wrote it that way because one of them is a pre-29 model made in 1957 and one is a 329PD (so I couldn't just say Model 29).
I had always assumed, though I can't say for sure why, that the gun used in DH was a very early, probably pre-29. I measured the barrels on all of my guns and found something interesting:
Pre-29: 6.5" barrel. Bright blueing (maybe this is why I thought Harry's gun was a pre-29?)
Mdl 29-6 (circa 1999): 8.25" (not quite 8 3/8" but my 1979 Mdl 14-1, Circa 1979, is actually 8 3/8")
Mdl 29-4 (circa 2000): Also 8.25"
Mdl 29-3 (circa 1982): 5.75" (not 6")
For comparison, in addition to the .38 special Mdl 14 mentioned above, I measured my 27-2 (circa 1975): 5 7/8" (not quite 6").
Another reason I assumed harry's gun was an older model is because it looks to me like it's a 6.5" barrel. I know that S&Ws have not used a 6.5" barrel since at least the Mdl -3. As someone wrote earlier, maybe 1979. I do know that S&W first made the 4" barrel available in 1960.
These guns are very special to me. When DH came out I just had to have one. I wrote S&W and was told (if memory serves) that, at the current production rate, it would take 21 years beofre I'd see one!
I bought a single action made by a competitor and never did like it. I couldn't hit an 8.5x11" piece of paper at 20 feet with it. I sold it when I found my 29-3 in 1982. Cost me more than $350.00! I took her out in the dead of winter, found several beer cans some idiot left in the woods, threw one as far as I could (about 30 feet) and it landed with the end toward me. First shot I put a 40 grain bullet right in the end of that can! The other five shots performed similarly. Seemed I couldn't miss with that gun! I have been hooked ever since.
Sorry for the length, but I could talk about these great guns all day and the Model 29 is responbible for my love of S&W today. Two closing thoughts:
If Harry "skidded" his 29, I think maybe that would have been in The Enforcer where it skidded off the pier into the ocean.
Also, I too have heard the .41 mag being used in DH and have always doubted that as I could not figure out why they would do it. Whatever, I wasn't there, but I'm not so sure I could tell for sure if the gun in the movie was a .41 or a .44 (the latter being only .020" larger in caliber).
Thanks again - m