[HerbZ]

Isn't our main concern with shooting a Luger, is that it functions properly, and without damaging the pistol. Then wouldn't the specification we should be most concerned with is muzzle energy? If the original German Army specs are a 123 gr bullet at 1,076 fps, that's 316 ft-lbs. May we assume that's a good solid amount of energy for safe and reliable functioning, and plenty enough "for war."

Then NATO spec 9mm of 124 gr at 1261 fps would have a muzzle energy of 438 ft-lbs. If I'm doing the math right, that's a 38.6% increase in muzzle energy. That can't be good for any Luger to run a couple of boxes through once in awhile.

So here's a real life problem. When Ohio's lockdown is over for sure, I've a nephew and some grands that want to shoot my byf 42. Everyone had already bought a box of 9mm at Cabela's. I certainly don't want to damage the P.08, but shooting underpowered ammo may cause malfunctions. There's a box of Sig; 115 gr FMJ, 1185 fps, 359 ft-lbs, another kind of Sig; 115 gr FMJ, 1050 fps, 282 ft-lbs, and a box of PPU; 115 gr FMJ, 990 fps, 250 ft-lbs.

I know we can't be absolutely certain of any of these specs, made in the USA or Serbia, but they're all I have to work with here. I'm thinking the hottest is too hot. Maybe the middle one is in the Goldilocks zone? Is the PPU ammo too underpowered?