Quote:
Originally Posted by grantman
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?
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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