JimTom wrote:
Mate I use it for the 300AAC and 357 Mag.
I've loaded some very usable loads of 357 Mag using ADI AR2207 which is a little slower than 2205 but is the fastest powder currently available in Australia. For a given 2205 load it takes about 20% more 2207 by weight to get similar results but obviously it's better suited to longer barrels.
I use a 16gn 2207 load with magnum primer and a 180gn powder coated lead projectile in my 357 silhouette loads, they work very well through a 10" TC barrel but leave a noticeable amount of unburned powder with a shorter 6" barrel in a 686 revolver.
2207 is actually a listed powder for 300 Blackout for heavier projectiles and would likely still be very usable for the lighter ones if you can fit enough into the case.
It's a tough fact right now that if our stocks of our usual powder run out we will have to develop new loads using less than ideal slower powders.