It is amazing how far the brass flies with the 10mm.  Even factory FMJ flies a good distance. 

Ideally I'm looking for XTP 180 recipes as I have 100 on hand and 200 more on the way.  May consider going to Starline brass if I can't get the Win brass to play nice.

Shadow, what would you recommend if I have to switch powders?

Den, it is kind of a carryover from doing load development on the long gun side.  I figured that if it is good for load development for the long guns, it should be good for the short ones too.  However, I'm not sure that all of that theory carries over to the short ones.

I did a lot of reading prior to choosing the AA#9 because it sounded like a good powder for the 180 class bullets.  I'm beginning to think that it might not be the right one for my pea shooter from an accuracy standpoint.  Interestingly enough, although I was getting velocities higher than (Hornady) book for the 180 XTPs, when I used 180 gr. PC HC, they averaged slightly slower than the (Western Powders) book velocities.  I'll keep playing with it until I find what works with AA#9 or switch when I run out of it.

Based on my rifle loading experience, I would say that I have 2 accuracy nodes - 12.5 gr. and 14.0 gr.  I'll continue to work around those and see if things improve from an accuracy standpoint.

Shadow, it is a SA XDM 4.5" 10mm.

New to the 10mm cartridge, but have experience reloading other calibers (mostly rifle).  I've done a round of load development over the chrono and I'm getting much higher velocities than the book says I should expect.  Was going more for measuring velocity, but the accuracy at 25 yds was nothing to speak of with any charge.  100+ rds through the gun prior to load testing.  Any ideas what might be causing this? 

1 x fired Win brass, CCI 300 primer, AA #9, XTP 180 gr., 1.260".  Conditions: 45 deg., 30.07" Hg, 6700'.  5 shot strings.

Charge: 12.0    12.5    13.0    13.5    14.0   14.5
Avg:      1097   1164   1204    1232   1284  1315   
ES:        72       28      40        55      25      35
SD:        26.5    10.6   14.8     20.2    10.6   12.3

Hornady book max is 14.9 gr. @ 1250 fps.  I got pressure signs at 14.5 gr., so I stopped.  The numbers show I'm pushing 65 fps faster at .4 grains below max.  Something just doesn't seem right to me and not sure where to take it from here.  Any advice is appreciated.