I have a Walther PP Super. It uses the 9x18 Police cartridge. I believe that the 9mm Ultra is the same dimensionally, although historically they may differ. I think that the Ultra was an earlier version of the cartridge. Don't have my references here at the office. The 9x18 Makarov is a .366 caliber and not the same as the 9mm Ultra or 9x18 Police at all.

From time to time, Midway USA has the 9x18 Police available, either from Fiocchi or GECO. I have never ordered this cartridge from them, as I have a decent supply and don't shoot it much.

I have loaded the 9x18 cartridge, but it has been a while. I know that it uses the same .355 bullet as the .380. If I recall correctly, the case may be tapered, like the 9x19 Parabellum/Luger -- and unlike the .380 ACP which is straight walled. I think I loaded the cartridge in a somewhat makeshift fashion, using .380 dies, but only sizing the brass partially. Proper 9x18 dies were prohibitively expensive.

It isn't substantially more powerful than the .380 ACP, but I don't recall whether I used a .380 load exactly (likely either Bullseye or Unique). The reloads functioned fine. Sorry I don't have better details, but it has probably been 8-10 years since I played around with this cartridge. I came across some new brass for it cheap, or I probably wouldn't have fooled around with loading it.

A place called Earl's Repair Service, that specializes in German Walthers, used to have grips available for the PP Super. Mine is a used police gun and could use some new shoes, but they were too pricey.

Jeff