Interceptor,
The answer is yes, I can get a 320 power factor out the 300-221 fireball aka Whisper(r). I am not sure what you mean be "as fast as .223 minor". If you are talking about the recoil?... I can say that the recoil is only slightly more than my 223 and instead of being a "snap" it is more of a roll.
I can make 320 pf with 180 g bullets using several different powders. Currently my best loads for 3-guning are W296 (1830 fps and 1 in. groups at 100 yrds.) and Lil'Gun (1880 fps about 2 in groups at 100 yrds. This load may be a tad too hot. I have the run more tests and mic the cases).
See all of my reloading data at:
http://reloadersnest.com/frontpage.asp?CaliberID=135
My loads are listed under "Not yet verified user loads" All of the loads listed I have shot and chrono'ed, except the one using the AD2205 powder.
Now here is the best part. All of my 30 rd 223 mags work with the 300-221 fireball, including my beta-c mag.
As they say however, you can not cheat physics. The trajectory is NOT as flat as the 223. But if you practice and get you know your rifle and sights you can make the 200-250 yrd hits without too much effort.
I had Randall at AR15 Barrels.com (
http://ar15barrels.com/) run some QUICKLOAD models for me and he verified some of the reloading data that I have found on the web. It looks like it might be possible to make major with 155 g palma and/or 165 g bullets at ~2000 fps. I will let you know when I finish my testing.
Maybe we will run into each other at a 3-gun match
Here is the link that give the data on the rig that I am running:
http://www.quarterbore.net/forums/showthread.php?t=1151
http://www.quarterbore.net/forums/at...0&d=1163053744
320pf