2400 is one of 4 powders I've used a lot of. The comments below come from a well respected fella. However I cant say that I've heard some of what is said here accepted as general knowledge about 2400. It certainly hasnt been my experience with this powder. I would like to hear comments on this.... Jeff
Here's some data on 2400 powder. It was designed in 1930 for the 22 Hornet and later was used in commercial 410 shotgun ammo. Though the formula changed slightly since it first came out, it is still the most unstable handgun powder on the market. All powders change characteristics a little when different bullet weights, bullet seating depths, or magnum primers are used. 2400's burn rate changes radically with the above. It is also way more temperature sensitive than any other hand gun powder. As the revolver's chamber temperatures heat up, 2400 will burn way faster than the first shot. The most serious issue with 2400 is primers. The reason why magnum primers were invented was twofold. First, there is more "mix" in the primer to help ignite slow burning powders. 2400 doesn't like magnum primers because the extra mix speeds up ignition and makes chamber pressure skyrocket. Second, the cups for magnum primers are thicker to prevent ruptures at high chamber pressures affiliated with high velocity loads. 2400 DOES need the thicker cups as a safety margin .... but can't use them. It's a fact that many other powders do a much better job than 2400 with magnum loads. "Better job" doesn't mean 2400 can't be used but it does mean other powders have more consistent velocities, not as temperature sensitive, lower risk of a primer blow out, and equal or better accuracy .... all with lower chamber pressure and a better safety margin. 2400 behaves much better in 44 Mag loads than it does in 357 Mag loads. Personally, I would not recommend using 2400 powder in a 357 Mag, especially for a newbie.