Just picked up a new Blackhawk 41 magnum with a 6.5" barrel. Grip and ejector housing are aluminum. It feels about the same weight as my 5.5" barrel 44 special. The aluminum doesn't both me, and I like the fact that the longer barrel and frame size of the 41 mag doesn't feel excessive in weight as a whole.
On a side-note: The 41 magnum I received was actually better in build quality than my 44 special was. The 44 spl had dings and scratchs in the metal on the sights, casting pit on side of front sight, missing blueing around the cylinder frame area, and a light roll-mark on portions of the caliber stamp on the frame. The 41 magnum was flawless out of the box; couldn't find a thing wrong with it. I do like that the 41 mag has the barrel roll-mark warnings moved to the bottom of the barrel, out of sight. That is something I saw on the 44 spl and was hoping to find the same on the 41 mag. Makes the whole revolver look classy. Of course, BOTH shoot excellent. That's what ultimately is important
Few additional points: The 41 mag has an internal lock, but is out of sight. Also, the Blackhawk does not have the reverse indexing pawl, like the 44 spl and New Vaquero's have. I thought it would bother me that the clicks don't line up with the ejection of spent cartridges, but it was still easy to do brass ejecting. One downer, that I knew the Blackhawk would have, was the in-ability to remove the base pin completely. It bumps up against the ejector tab and can't be removed easily for cleaning like the New Vaquero or 44 spl. I've read that folks grind the base pin down to allow removing, but will have to research that.
I'll gladly include pics if anyone is interested in what I've mentioned above.