Observations on firing the .30 luger: problems, ammo, springs

[DonVoigt]

Update 4-29-2016

Getting the .30 or 7,65mm luger pistol to "run" can be a real challenge for sure; and it seems all are slightly different.

Some of the "things" that affect performance:
1.0 Ammo
2.0 Magazine
3.0 Mainspring
4.0 Barrel ramp
5.0 Extractor

6.0 Other

I'll try to address them in some logical and understandable order!


1.0 Ammunition: Bullet shape,material, velocity, and over all length(OAL or COA) enter the equation. Here is what I "think" I have learned to date.

1.1 Bullet shape
A round nose projectile, preferably jacketed is most desirable, Fiocchi Round Nose Soft Points will work in some pistols, hollow point projectiles will work in fewer pistols.

1.2 - Over all length
The original spec for the 7,65 mm luger cartridge was for 1.173 OAL
Most and perhaps all modern ammo is shorter in varying degrees.
Recent measurements are below, Fiocchi is found to be the shortest, PPU(Privi Partizan) the longest. I had no Finn ammo to measure, so if someone can advise I'll add it to the list.

Table 1.2
Manufacturer measured : OAL in inches

Winchester: 1.141 to 1.151
Remington: 1.138
Peters: 1.137
Rem-UMC: 1.139 to 1.144

Fiocchi: JSP- 1.114 to 1.119
ball- 1.115 to 1.119

PPU : 1.160

1900 spec: 1.173

So from the short Fiocchi to the long PPU- we see a difference of 0.045" or about 1.1 mm!
Less significant is the Winchester at 1.145 vs. the PPU at 1/160 or 0.015" , but still about 0.1mm

1.3 I have been struggling to get my custom project "baby luger" to function. It has a 2.5" .30 bbl and the grip is shortened 1/2". Thus the mainspring and mass are both changed from the norm. Until today I could not get ANY ammo to feed reliably, getting an "angle" jam at least every other time. Switched to the longer PPU, and the load and function is perfect. NO jams, and locks open. A separate thread will be one on building this "baby" when the project is complete; I plan to have both 7,65mm and 9mm upper assemblies for it, the 9mm is in fabrication with GT.

Which brings us to the Second Problem: the loading, or muzzle velocity.

1.4 - Muzzle velocity ..... to be continued!