Hi,

German Army round nose ball was loaded between 1.169 and 1.173 inches. For best function in a Luger, with Meg-Gar magazines, these lengths will feed very trustworthily.

Those powder charges seem way too high to me, but i would have to shoot your actual loadings to verify this. If you are experiencing breach-block slam at these charge weights, you will eventually damage your very fine Luger.

Respectfully,


Sieger

These loads are posted in Speer manuals #14 & 15. For AA#7, the range is 8.6 gr. to 9.6 gr. The 8.6 grainers, fired from a S&W 5906 claim a velocity of roughly 1158fps. I'm loading between 8.5 &9.0 gr. I have yet to chronograph these loads, but I'm guessing the 8.5 grainers will offer less than 1158 fps. Examination of fired cases reveals no excessive pressure signs with either 8.5 or 9.0 grains. The charge weights may seem heavy to those using unique, 231 or bullseye. AA7 is a bulky powder in comparison, but was formulated for 9mm and similar cartridges. In fact, Speer lists a max load for the 9mm Makarov at 8.0 grains. The Mak has a working pressure max of 24,100psi while the 9mm luger operates at a max of 35,000 psi, per Speer. This is interesting stuff, no?

Hi,

I don't think pressure (within reason) is the real issue here to any great extent.

The inherent design of toggle system of the Luger is. This system requires a specific balance between ammo and springs for proper, accurate and reliable function (without damage to the pistol itself). Neither the Mac nor the S&W, you site above, are hampered by these restrictions.

When I can find the time, I will be writing a very detailed explanation of breech-block slam and how this will cause a Luger System to eventually fail mechanically.

Respectfully,


Sieger

Interesting....what would be the determinant of breech block slam? I would think it would be determined by rate of combustion and pressure curve.

Grantman - there are posts on how to check for breech-block slam - basically using a small bit of masking tape at the back of the toggle/or breech-block at that point. I am sorry I cannot remember the post but had photos to demonstrate. If the paper was cut the travel is too severe - back off the powder a bit.

Like any reloading the best charge is the lowest that will cycle the action.
Don't beat the gun to death.
The reloading challenge is to find the combination of bullet and powder that will do that with the greatest accuracy.

[QUOTE=Kiwi;334698)

Like any reloading the best charge is the lowest that will cycle the action.
Don't beat the gun to death.
The reloading challenge is to find the combination of bullet and powder that will do that with the greatest accuracy.[/QUOTE]

Agreed completely!

Sieger

No sign of this on any of my Lugers. AA#7 is said to be a powder especially formulated for 9mm. it's originally an Israeli formulation. It is claimed that AA7 produces high velocities without excessive pressures. Thanks, Kiwi

The only problem I have with AA7 is the granules it leaves in a Luger's action. I have no such residue with CFE Pistol.

Hmmm....I have found AA7 to be exceptionally clean-burning. And your previous comment was correct ....I have been loading round-meplat FMJs. WW white box, even though round meplat, offered less reliable function. I measured these at 1.163"+ . I tried mag-tech 115 FMJ, which measured 1.155" and it offered much greater reliability. I have had best function with 1.155" to 1.160" COLs.