Greetings from Central Oregon.
I'm fairly new to reloading and have spent the past couple of hours trying to find reload data for (polymer coated) 200gr hardcast. Seems to be the biggest secret on the planet
So, I have the above mentioned combo of Badman's bullets (local Oregon supplier) and Accurate #9 which I want to put to use.
I was thinking about a COL of 1.250" and working my way up to 1,100 ft/s. Would 10.5 gr of accurate #9 be a safe start ? I have a ballistic chronograph to measure progress.
Also, I want to use these bullets both for plinking and wilderness defense (black bear and other Oregon undesirable species). Any suggestions on how to develop optimal loads for both occasions ? Thanks !
My 10mm Handguns : full size S&W MP2 and XDM Elite Compact.

Welcome The Gaul, I?m sure some of the others can assist you with your powder choice, Enjoy!

Greetings Gaul,
I just recently worked up a load Using 200 grain WFN gas checked Montana hardcast bullet. I'm shooting a stock Glock 20 Gen 5.
I started At 11.5  of A#9 and worked up from there and I ended up getting decent accuracy over 12 grains of #9 and never went above 12.6 grains. I was seeking 1100- 1175fps in my gun.  This put me in my gun over  1100 FPS but not up to 1200 fps. Im using COL: 1.242 to ensure it feeds well.
Do you have a chronograph?  I would start where your comfortable and work up slow and carful till you get a safe load for your gun and barrel length that does what your seeking.

Thank you Huntchick, your numbers make sense. Yes, I do have a chronograph and can shoot on my own property, which helps for a quicker load development.
So far I have been using some Win231 for plinking. 6.5gr of that stuff combined with a Nosler 135gr JHP results in 1,150fts. I was a bit apprehensive pushing things above 10gr on the Acc#9, seems to be a way less economical powder. Is it getting close to compressed, once you hit 12gr ?

I normally shoot at home also unless it?s nasty. Definitely helps having a home range.
Using new starline brass and a 200 gr. XTP or 200 gr. Montana WFN bullet I get 12.5 grains #9 without noticing anything getting compressed. I believe somewhere above 12.5 maybe 13.0 it would be getting compressed. I?ve not myself gone over 12.7
I measured a 200 XTP to where I seat it and then added 12.6 grains #9 in my brass then took a 9mm case and inserted it in the 10mm case onto the 12.6 then measured the 9mm case that was sticking out of the 10mm case. Basically did the math and at 12.6 it was really close to being compressed with the 200 XTP and 12.5 of A#9. Hope that makes sense.

    I too load the MT Bullet Works Hard Cast 200gr WFN GC bullet with A#9. Using Win. or Starline cases with WLPs, 12.5gr of A#9 gives me 1262FPS out of a Guncrafter Industries 1911 with 6" Barrel. My son gets similar results out of his DW Bruin. OAL is 1.250.

AA#9 is a great and safe powder for 10mm; it's hard to get an overcharge with it.  Of course  it's good practice to start low (or mid-range) and work up the load.