The CZ P-09 is polymer gun that is quite accurate. I have been working up loads and feel I have found a few things that improve accuracy in my gun. Getting a ransom rest really helped pin down what is effective, but it is technique sensitive.
Here is a video of my load with 115gr hornady xtp's, 6.0gr of power pistol, COAL 1.125, federal gold match primers. The two 10 shoot groups measured 1.18 inches and 1.35 inches at 50 yards.
Here are some things that helped with my gun.
-Maximizing accuracy with the ransom rest. I started using the ransom rest like the AccuracyX videos (which are amazing by the way!). I stumbled upon an alternative technique. I attached a string to the ransom rest and pull this back with my left hand and quickly return the ransom rest with my right hand. This allows it to be very consistent. You can see this on the videos I posted below from my powder work up on some 115gr HAPs.
-Used starline brass cleaned with wet tumbling (I use the Franklin platinum tumbler) and lengthened with the EGW U-die, the average length even with multiple firings is 0.750 inches.
-Expanded to just allow the bullet to slip in using the Custom Powder Funnel from Uniquetek.com
-No crimp
-There aren't any oversized match barrels like for 1911's, so I added some epoxy to the side of the barrel, opposite of the extractor. This helps tighten up the slide to barrel fit, and on the CZ the slide to frame fit is quite good.
Here are some videos of a powder work up with power pistol.
6.2gr power pistol
6.0gr power pistol
5.8gr power pistol
Wayne