9mm cost

[thedishdoc]

Takes a hotter round to cycle that toggle bolt. I think the Germans shot a bigger bullet than 115 grains also.

[Dale Gribble]

P38 doesn't have a toggle bolt, its actually like a crude version of a M9 when you look at it. But my guess is that you are pretty close to right, they probably built it with stronger springs to withstand the same ammo used in the Luger. As it is P38/P1's have issues with frames cracking.