I did some experimenting with a number of 85 to 110 gr bullets in my 1920's vintage Luger 15-20 years ago. As well as several cast bullets of my own construction. With Remington 110 gr FMJ carbine bullets, 4.2 gr of Win 231, WSP caps, in W-W brass with the bullet seated to 1.190" gave me 1.25" gps at 25 yds from a rest. It functions my 4" Luger well and I worked up to it slowly, weighing all charges. It doesn't SEEM to be hot, tho without sophisticated measuring equipment, who's to know. That's a heavy bullet for the .30 Luger, and impacts 3" high at 25 from my gun. Getting a decent crimp was tough and I wanted to try a more case filling combination that would help prevent setback as the round chambered but never got around to it.
That 4.2 gr load of Win 231 was fine in my gun, but you should work up your own with due regard to pressure signs and after consulting a GOOD current loading manual.
Hornady .32 caliber 85 gr old style JHP's also worked extremely well with nearly equal accuracy. Newer XTP's would not feed in my gun no matter what charge I tried.
Sierra .32 caliber JHP's fed well and chrono'd 1175 fps with 4.5 grains of 231 pushing them. Again, my load in my gun, work up for yours.
Since you've got the 110 gr Carbine bullets, I guess you're committed to that route, but I had more success with the lighter weights in .32 caliber. I'd slug my bore if I were you, and try the .32's. Cast bullets offer another, cheaper solution with a cpl good designs. A CLEAN bore, free of jacketed fouling is essential to good grouping with them. Bore condition is secondary to cleanliness in my experience in this caliber. I used 50-50 alox/beeswax at the time, but now I'd probably also swirl lube them with Lee Liquid Alox or White Label's 45-45-10 to prevent leading.
Another good option is Hornady's .32 calibler 90 gr Swaged SWC's if they're still made. The soft alloy Hornady uses allows you to turn a good crimp into the bullet and still maintain accuracy. I don't have notes regarding functioning, but did use Bullseye, and Unique with them. Accuracy was in the 2" at 25 yds area. The Bullsyeye load took 3.0 gr to get ejection and feeding right...same cautions with this load as with the others. Didn't note the Unique load however.
It's a fun gun to shoot, surprisingly accurate for its terrible trigger, but chasing those vertically ejected casings all over hellshalfacre is a RPITA. Too, those casings are getting tough to find for me here in Louisville. Shooting a Luger on today's ranges gets some long looks from the tupperware crowd of blasters...especially those tight 25 yd groups. Gun Pic below.
Hope you made out ok during the quake some years back. Our friend in Hastings, N. Island was unaffected but another down near the cathedral in Christchurch had significant damage.
HTH's Rod