Your gun is not a P-38. It is a P-1. Aluminium framed post war model. Takes the same mag, parts all are inter changeable.
I had one for a while and liked it. When a buddy had some dificulty I gave it to him as he had to sell everything and I wanted him to have a good handgun. He still carries it in his truck as an emergency gun.
If you look at it, you can see where Berretta got the ideas to build the 92.
And I remember mine likeing either the Win Silver tips, the Winchester 147 grain sub sonic, or the Rem Golden sabers as a hollow point. I have three WWII 9mm at the time and one liked one type each.
I had a Luftwaffa Astra 600 and a Mauser 96.
But as others have said ball works.