Odd experience with 9mm cases

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kmw1954

New member
Today while loading up a small batch to test some primers I've never used I ran upon this.

I sort cases by head stamp before I load just to help keep uniformity. So I was going to load 50 rounds with some S&B primers that I just received and have never used before.

I had a small group of 40 Perfecta brass I wanted to use up and then sorted thru my odd headstamp brass and found 10 with a PPU head stamp to make up the 50.

Started with the PPU brass and found my OAL and powder charge thru my Auto Disk measure jumping all over the place which is unusual as it's pretty spot on. So I got thru those 10 cases and onto the Perfecta brass and everything went right back to normal. OAL stabilized to within .002" and weight steady at my set point within .05gr.

Never seen this happen before! I've been using these same components for a long time. The only change was the brass.
 
I don't use the Auto Disk. Are you charging through your expander die? If so, is the feel any different when expanding (and retracting) the different brand cases?

Lee says the "jerk" when retracting cases is to settle the powder measure. I don't like the feel of it but I charge separately anyway. This (.40 S&W) is my first set of Lee pistol dies. I like their rifle dies better. In fact, if I had known that the "factory crimp" die is just a taper crimp, I'd have gone with RCBS. I may yet.
 
Can't say that I noticed any measurable difference from one to the other. Resistance was normal and no unusual sounds. It's just weird. So I don't know if the brass is softer or thinner or what.
 
I also sort by headstamp - mostly to get rid of the undesirable brass that shows up. I have noticed some of the headstamps have some quirks and some are just this side of junk.

I have found PPU brass to be a bit problematic after a few reloads. The case may cock in the shell holder during priming botching that or that when belled to accept the bullet it springs back stopping the bottom of the bullet from entering the case mouth - same goes for crimping. When they start either of those characteristics I will take what will load and take them to the fufu range near work that has the "no brass policing" policy.

BTW: For years I have loaded CCI primers into S&B brass and complained about the tightness of the primer pockets. Last year I got the S&B primers and that issue went away. I have been pleased with the S&B primers.
 
So yes I load with a Lee turret and a Lee measure which hasn't been a problem and all loads up to this have been consistent. What amazed me was how these cases seemed to effect the powder throw. The Lee Disk size .40 usually is a very consistent 4.3gr of HP38 but with these cases it was all over, between just above 4.1 to just over 4.3 then after I switched cases it went back to a steady 4.3gr.
 
That is a mystery all right. The jarring effect of the Lee expander on the powder measure is the only thing I can think of but mine does this with all brass. I suppose if it did not "jar" with a given brass, that could have such an effect.

And the OAL changing is a stumper. Surely that is not a compressed load? I've never used HP38 in 9mm but doubt that it is anywhere near 100% fill. No, the Nosler manual says around 60%.

I'd be a little leery of that brass until I figured it out.
 
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Yeup it's got me befuddled. I've loaded quite a few if these Berry's bullets and they've been very consistent. Last I loaded were these same bullets set at 1.130" and were steady at 1.127 to 1.130". Then with these cases it dropped to 1.125 to 1.122" w/o ever moving the die. Then when I finished those 10 and started on the Perfecta brass it all went back to it's normal steady operation, again w/o making any changes.
 
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