..., 20 rounds with Fed HST 124 and had at least 5 FTFeed. DOES NOT LIKE HST! I think the leading edge of the bullet contour of the JHP is hitting the top inside of the barrel entry (throat) ; the feed ramp on the P09 is short and steep.
What JHP ammo is anybody shooting that feeds well?
If the ramp, etc, is the same as the P-09 and P-07, then Atlanta Arms 115 gr JHP runs 100%. But that ammo is not very hot. The bullet shape, however, seems to be fine for the CZ dimensions and ramp shape. It is almost conical instead of a bulging and rounded in a side view. Since I don't reload, and since I pretty much standardized on the AA 115 JHP over 10 years ago for both range and carry, I don't even know how to describe the bullet shape and certainly haven't kept up with other options.
I have one other recommendation and that is IMI 115 gr JHP. It also runs 100% in all my CZ's. And it is accurate and consistent in the 4" and 4.5" pistols, maybe a little less consistent in the 3.5" P-10S than the AA. I am thinking the powder burn rate is a little slower than the AA powder, but, here again, I don't claim much knowledge in this area.
I am sure there are other JHP rounds that will work, but I have no need or desire to do any research. I have two excellent options with thousands of rounds of experience with each with no feeding problems and with proven consistency and accuracy. I'm not even willing to try 124 gr versions. I'm old and bullheaded...but I get good results.
Joe L