I'm just speculating based on size here (and caliber/cartridge) you're probably needing an N Frame holster. The J is S&W's small frame, the K/L are mid-frames, generally in the .357mag 6 shot ballpark. The Taurus 44 is a large framed .44mag, just getting 6 shots of .44mag in a cylinder tells me it aint going to fit in a K/L frame holster.

For what it's worth, comparatively, the 4" Taurus 44 comes in at 45oz, and the 4" N-Frame S&W 629 comes in at 41.5oz. The shroud on the S&W is a bit shorter, might make up an ounce, and the top rail is a little heavier on the Taurus, but by and large, I'd say if anything the Taurus is BIGGER than the N-Frame, if not about the same size.

No matter how you cut them, a 6 shot .44mag is a big dang revolver, ain't gonna fit in a J/K/L frame holster.