Thread: 7.65 parabellum
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Unread 03-17-2002, 11:09 PM   #19
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Default Re: 30's

Hello Rick,


I'm really seriously wondering if the correct diameter for the jacketed bullet isn't in the range of 0.311 to 0.312. I don't know where I would get a 32 ACP bullet and they generally run too light any way. I know there are some people using bullets intended for the 32 H&R Mag, these are the standrad 0.312. They say if you run a jacketed bullet through a cast bullet sizing die you can squeeze it down provided you do it in 0.001" steps. (The 32 H&R Mag is an odd one in that it has TWO correct bullet diameters, the 0.312 in revolvers and 0.308 in some single shots. I used to run 0.312 cast bullets intended for the 32 S&W in my first 30 Luger.


I very seriuosly doubt the Winchester load is too hot. Winchester claims 93 gr at 1220 fps from a 4.5" test barrel. I have an orgiinal owner's manual in German for the DWM Model 1920 in which they claim 1223 fps from the 3.9 inch barrel on the actual pistol. This means the Winchester load is slightly lighter than the DWM load.


Incidentally, the correct term for the measure of the load's ability to operate the action is impulse, not recoil. The concern here is obtaining the correct impulse. The action is very strong and there is plenty of margin for pressure. Keep in mind that the old flat spring carbine working load was the same as the proof load for the pistol.


This action will stand up to 32,000 psi from now until the cows come home. Winchester's data for handloading runs around 23,000 psi at 1080 fps.


So any body out there going to measure a barrel and tell us what you come up with?


In about two weeks I hope to be able to run some of the factory loads over the chronograph.


This mess is not a first. I have a rifle chambered for the Purdey 400-360 2-3/4 Nitro Express. Almost anything you can find in print about this cartridge is dead wrong.


Impulse = bullet weight in grains X muzzle velocity + powder charge in grains X muzzle velocity of gas, all divided by 7000 to convert grains to pounds. (Not slugs, that's another story) Since it is pretty difficult to get an actual measurement of the average velocity of the gas it is usually considered to be 2000 fps for a smokeless pistol load.


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