My limited 7,65x21 Parabellum~.30 Luger experience is that you have to load them "hot".
With a 93grain bullet pressures can be held in the medium/high zone.
With ie. a 73grain bullet the way hot loads comes in as it is momentum that drives the recoil/reloading.
So when bullet weight goes down speed has to move up to compensate.
The top of my 95mm~3.75" barreled pistol weighs 422gram~.929lbs and needs a recoil energy of @2.2joule~1.63ftlbs to reload reliably.
So:
Original DWM load 93grain bullet at 1213fps (1.64ftlbs)
A 73grain bullet needs to go @465m/s~1525fps (tall order!)
A 85grain bullet needs to go @399m/s~1310fps (my reloads from sunday went @382m/s~1253fps and did'nt reload at all. Not a single one out of 100). 1310fps is barely doable within pressure limits with the powders i have acess to.
All y'all with longer barrels are better off as speed comes free from the fact.
85gr jacketed bullet set to 29mm~1.14"
4.7gr Bullseye is about max.
5.2gr Unique is about max.
6.3gr Longshot is about max.
5.8gr WAP is about max.
These are the only US powders that will give a complete burn in such a short tube and keep pressures below max.
Bear in mind that this is guestimates made with Quickload and as always YMMW.
I have good results with Lees 93gr .311 bullet cast to 86gr (94% lead + 3% tin + 3% antimony).
Pushed to @1280fps it reloads reliably every time and ejects with autority.
As a lead bullet is easier to push through, pressures are lower and speed comes a result of that.
On a sidenote i have a Heckler & Koch 630 roller delayed blow back semiauto in .223.
That pig needs to be spanked in order to reload reliably. Drop MV 10% from max. and its transformed to a manual repeater.
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