The SS192 is no longer imported into the US - for over two years now. The SS195LF has a Lead Free primer. Some people say the are indentical except for the primer.
The SS198 is the same as the SS195LF EXCEPT the SS198 has .2g more of the factory powder (this was reported but I can not vouch for the accuracy of the .2g as I have not taken apart a SS198 round). That .2g of powder gives the SS198LF the higher velocity of 2050fps compared to 1930fps of the SS195LF.
I would like to see the read outs of the Chrony. The deviations, hi, lo, and spread. If both the SS192 and the SS198 measured the same velocities of 2050fps then there is a problem here because the SS198 is suppose to have a higher powder charge than the SS192/SS195
That means the SS198 has 253 ft-lbs of stopping power at whatever distance the chornograph was set up at from the muzzle, at the point that the velocity measurement was taken. Increase the distance, velocity decreases, and so does stopping power.
The SS195LF has 224 ft-lbs of stopping power at 15 feet from the muzzle due to its lower velocity of 1930 fps.
For impact power, either the 40g or 45g bullet with the appropriate amount of powder is the best bet. That will give you 310 ft-lbs and 327 ft-lbs respectively in the FiveseveN. You give up 190 fps and 250 fps of velocity compared to the SS198 but only 70 fps and 120 fps compared to the SS195 using these two projectiles.
For BPx69: I can not say for your specific needs due to the rules that your department places upon you. There is aftermarket ammunition out there that is better than the FnH stuff (if you want to stay away from AP rounds) but these rounds are disassembled and rebuilt using various non factory items. FnH made the SS198 specifically for LEO as there can be direct sales and it is hotter than the SS195 (big woo hoo here). For the SS190, you need department head memo and the challanges that come with it. I load and carry my own and am under no constriants except the Federal AP rules limiting the use of a certain designed projectile in the FiveseveN.