The original 9mm bullet was 124 grains (8 grams), soon reduced to 115 grains (7.5 grams.)
My only Luger was a P08 long ago. It shot Canadian surplus great, but when that dried up and all I could get was Remington commercial, results were not good. I soon sold the gun.
I know more now and I see that Remington 9mm is shorter OAL than other brands, which works against the Luger's slanted magazine.
I would look for the longest OAL ball ammo I could find. You need full charge ammo to drive that long barrel, but Lugers do NOT need "hot" ammo. As one Luger fan said, an overloaded Luger behaves a lot like an underloaded Luger.
On the other hand, a friend's 1923 DWM/Tikka does best with my 145 gr subsonic. But still a roundnose loaded rather long.