Feeding problems in a Luger,,,look first at the magazine,, it's spring and the follower. They are the cause of most of the malfunctions both in feeding and ejection in Luger pistols.
Stove piped loaded rounds half out of the mag,,the toggle recoiling far enough to eject but not pick up a fresh round, an ejected fired round and the toggle closed on an empty chamber,,these and other feeding/ejection problems are generally magazine problems and not necessarily the ammunition
Most all of mine feed/fire/eject off the shelf 115gr Rem-UMC FMJ with little or no faults once a 'good' magazine is matched up to the pistol. You can't simply tell by looking at it, slapping it in place and yanking the toggle back.
Make sure the holdopen spring has sufficient power to secure it in the 'down' position while firing. If weak, broken or missing completely (the gun will operate w/o the hold-open spring), the holdopen can bounch up into place and block the toggle in the open position with live rounds still available in the magazine.
It will appear as a fail-to-feed w/the toggle stuck open.
As the toggle is pulled back a touch,,the holdopen then falls back away and the breech is released, feeding the round sucessfully this time.
Check the firing pin spring and make sure a heavy weight replacement isn't installed to 'improve ignition'. It may do that, but it will also induce fail-to feed as the last motion of the closing breech block/toggle cocks the firing pin.
If that last 3/8" or so forward motion
of the breech block is held back by a extra strong spring, you'll get cartridges chambered but the breech not fully closed.
A reduced power or clipped main spring can do the same or add to it.
Meg-Gar replacement Luger magazines work well if an aftermarket replacement is needed. Another original Luger mag may do it,but it may also be worn or worked over (feed lips) or a weak spring.
The catch slot can be worn a bit too allowing the mag to sit low. That causes feeding problems too. It can also cause the holdopen not to engage all the time on the last shot.
High pressure loads aren't needed in a Luger any more than they are in any other semi auto pistol. What is needed is a load of sufficient energy (recoil) to operate the system. You don't necessarily need extremes in pressure to get to that level of recoil energy.
Light/minimum loads will generally not operate a Luger any more than they will most factory stock CF semiautos.
Work up a load with a round nose FMJ or cast bullet and you will generally find a load the feeds and ejects well in a Luger.
I like the 115gr, but I also use the 95gr cast RN bullets intended for the 380acp . (They were cheap!)
They've worked very nicely using RedDot in a couple of Lugers, a 1908 Commercial and a '41 Mauser. In the slightly heavier '17 DWM Artillery, no go.
But 115gr commercial & handloads works OK in the LP08.
Some tweaking of any load (OAL effects feeding alot in these), helps to
squeeze reliability from it.
Some will feed/fire/eject most anything,,others are stubbon and it takes some searching to find the right combination it seems.
But I've never found it necessary to go anywhere near Max loads in any Luger to achieve reliability.
They are anything but new pistols any longer. Some are 100y/o and more. Many are of unkn history and have been rebuilt any number of times.
Take it easy on them. They are great handguns, fun to shoot.
I'd rather accept a few FTF here and there rather than run the loads to the max+ in a search for a 100% reliability CCW round for one. They are expensive historical curiositys now.
Just my thoughts..
