velosity variance in handgun ?


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joneb
March 15, 2012, 12:22 AM
So when chronograghing handgun loads do you concern yourself with case weight variations in the brass ?
I am trimming down some 9x19 S&B to 9x18 and I'm noticing a variance in case weight, since the external dimensions are the same I can only assume the internal dimensions are not.
Those with chronograghs seem to be concerned with SDs and ESs but are they concerned with case weight variations in the brass ?
Thanks
How did I spell velocity wrong :confused:

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rfwobbly
March 15, 2012, 12:55 AM
I don't. If you need a consistent load, then using the same brand brass throughout a batch is all you usually need to do. They'll always be some variation, but the greatest is going to be in mixed brass.

joneb
March 15, 2012, 01:59 AM
Thanks rfwobbly,
I am trying out a new pistol powder and I am considering variables, whats next ? you guessed it I'll be weighing my primers :scrutiny:

1SOW
March 15, 2012, 02:48 AM
whats next ? you guessed it I'll be weighing my primers
:D

Fed SPPs will give a slightly higher avg speed than others. SPP Magnums will give slightly higher yet. The speed increase will vary some depending on the powder.

Walkalong
March 15, 2012, 01:23 PM
9MM brass varies wildly in wall thickness and weight. Sorting could only help, but could you could see it on target?

Powders make a difference in ES & SD numbers. Sure do. So does the pressure level.

GLOOB
March 15, 2012, 03:41 PM
Differentiating your 9x18 from 9x19 causes enough grief, as it is. If you're gonna spend the time to cut down mak brass, the least you can do is settle on one headstamp. Preferably a headstamp with sharp lettering that holds red Sharpie, well.

rcmodel
March 15, 2012, 04:02 PM
+1

Sort the cases by headstamp.

Not only are internal differences going to change case capacity.
But web thickness is gonna change seating and crimping requirements/.

BTW: I hope you pick them all up when you shoot them.
It is a real PITA to find a bunch of cut-off 9mm in your 9mm brass!!

rc

joneb
March 16, 2012, 12:39 AM
I hope you pick them all up when you shoot them.
It is a real PITA to find a bunch of cut-off 9mm in your 9mm brass!!
I do my best, but I am lucky to recover 90%.
I traded/sold my G/17 and G/19 so I just have the East German Makarov now. The 9x19 brass I have is free range brass, the FC and S&B seems to be the thickest at the case mouth more so than GFL,RP,Win and PMC. I have 300ct of Sierra bullets I got cheep on close out they are .363" dia and my groove diameter for this pistol is .365" I loaded 50 with various charges of W231 and AA#5 in 9x18 brass with poor accuracy, my gut is telling these bullets are to small and then I thought maybe poor neck tension. I have RCBS carbide dies so I acquired another expander/flare stem I can turn down or I can use thicker brass, so I'm going to try the trimmed 9x19 S&B brass and see how that works.

I am seeing a case weight variance of 2gr so I will sort it for testing. I am curious if anyone has found a velocity difference with 9x19 because of a 2gr difference in case weight ? Maybe I'm over analizing this :confused:

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