And the first XTreme 124 HP data is in. I have lots of data with lots of different bullets with this powder now, so I started a little higher than I would have if I was new to the powder. Here it is:
Powder: IMR 7625
Primers: CCI 500
Brass: Starline -- Once-fired
OAL: 1.08
The results from the ProChrono:
4.3gr 1014 fps avg ES-26 PF-125
4.4gr 1039 fps avg ES-32 PF-128
4.5gr 1057 fps avg ES-28 PF-131
I should add that I started to run a string at 4.6 grains, but the the first few velocities came in 5-12 feet/sec faster than 4.5 grains, plus one anomalously higher, so I didn't finish it. I kind of wish I had finished it now just to know, but I got to a PF of 131 with 4.5, which is all I want, so I didn't pursue it. As I sit here typing this, I realize that I haven't tried to get any 124 grain bullets higher than a 135 power factor with 7625, so it could be 7625 is fast enough that it's approaching its limit in the 1050 to 1100 range with various 124 grain bullets.
Accuracy was normal at 10 yards -- small and tight. At 25 yards... I honestly don't know how to assess it. I really don't know what's good. And I think I've gotten old enough that my vision is starting to become a factor. I'll post a pic later. It's a 10-shot group, and it's about 3.5 inches at its widest and 3.25 inches at its tallest. And this is off of a benchrest. I can keep them on a sheet of notebook paper at 25 yards offhand, but not 3.5 inches. As I sit here and look at it, I have to think most of the spread is me, so I think the bullet is performing admirably.
