I am currently using 17.0 grs. of 296 with a 158 gr. hard cast commercial SWC. It gives exactly 1200 FPS out of my 627 with 4" barrel. Accuracy is outstanding and for me it's an easy load to control when shooting fast DA. There's a lot of blast and significant flash, which leads me to believe all the powder isn't being burned in that 4" barrel. I have a large quantity of this stuff loaded, the reasoning being I can sell it if necessary to somebody who has a long barrel revolver or carbine. But it's still a decent load even in the 4" barrel. I get a little leading near the muzzle and I was worried about unburned powder clogging up the chambers, but I am able to do fast moonclip reloads that just drop right in the cylinder with no problems.
All said and done, I prefer 14.2 grs. of 2400 which gives the same velocity with less fuss.
I have never used 296 in the .44 Magnum. I prefer 2400 in all magnum revolver cartridges unless heavy for caliber bullets are used.
Dave Sinko