30 Luger Cartridge Conversion

[sheepherder]

This looks like a good place to link cartridge dimensions from an old COTW...

[sheepherder]

I was loading up five 30 Luger cartridges for tests in my 7.65 Parabellum-chambered Star BM and took out some brand new Winchester 30 Luger unprimed shells to set my RCBS dies up.

After setting the dies up, I started to run my shortened & sized 5.56mm Remington/NATO cases through the seating die and I was running into OAL case length issues...

It turns out the new unused Winchester shell cases are too short for 7.65 Parabellum specs...They run .840" and the accepted tolerance is .845" - .850" OAL...

The Winchester cases have .005" to .010" less neck. That means they don't grip the bullet as well as a full-length case.

I'm setting my case trimmer to .850" to get as much neck as possible.

Just a heads-up, if your die doesn't seem to be taper crimping the Winchester case neck down tight enough to hold the bullet securely...

[sheepherder]

I had a chance [first light] to shoot five rounds of my 5.56-to-7.65 conversion rounds today. 86gr JLRN bullet w/3.5grs of Red Dot and 4.0grs of Red Dot. Both loads out of a converted Star BM (barrel conversion detailed in another thread). (My 7.65 Luger is disassembled for barrel change).

The 3.5gr load was a pleasant surprise. All five rounds on paper. The 4.0grs load only cut paper once in five. No cycling in all ten, no ejection, and eight FTF's. Need to play with springs. I was hoping that the 7.65 would be a straight swap with 9mm but not the case. I may try a 4.3 or even 4.5 grain load of Red Dot, but the case is nearly full with 4.0grs. I stay away from compressed loads. I liked that the 3.5gr load was on target with no sight adjustments.

Star BM recoil spring is 'captive'. Easy to field strip & clean but difficult to change. I have two of these steel frame Star BM 9mm autos; one Israeli police surplus, one Spanish Guardia Civil. I'm thinking of re-springing one to 7.65 Parabellum. I have quite a few Star BM/BKM parts, just have to experiment with the springs...

Anyway, no problem with the case conversions. I was going to save the bright new Winchester cases for when I had the loads worked out for the Star but since they're out of spec I'll just work them in with the 'homeboyz'.