Really expensive is an understatement! $25 a pound plus hazmat makes it extremely expensive. If it ever gets available locally, I would consider it, but for now, T7 works great with the musket ignition.

I shoot 120gr loose 2f T7 but use musket caps and don't have a problem with seating the 2nd, 3rd or 4th bullet without cleaning. The "crud ring" problem is most often associated with the use of the 209 ignition which isn't legal in Washington state. The 25ACP conversion was created to preclude the crud ring problem with the 209 ignition from what I've read.

http://www.prbullet.com/hornet.htm

Higher pressure and the infamous "fire ring" of crusty powder left over near your breech (if you use pellets) that keeps you from making firm contact with the powder when seating your second bullet.