Why Separate Cases by Headstamp?

[sonic306090]

Hello Everybody,

Do you separate your cases by headstamp before charging? What are the pros & cons of separating?

[Green Frog]

Cases from different manufacturers and even different lots from the same manufacturer may have different capacities, thickness (especially neck) and other differences which can affect your ultimate consistency, especially for bench rest or other precision shooters.

Froggie

[GasGuzzler]

No.

Unless I do.

Your question has 5244615 variables that lead to anyone's answer.

[sonic306090]

Well, I read that people separate cases by headstamp. I was wondering because I use all different brand 9mm cases and when I weigh a finished cartridge, The weights are off by a few grains. So, I started weighing the empty/decapped cases and they were different by a few grains of each other. Is this common?

[GasGuzzler]

Well, I read that people separate cases by headstamp. I was wondering because I use all different brand 9mm cases and when I weigh a finished cartridge, The weights are off by a few grains. So, I started weighing the empty/decapped cases and they were different by a few grains of each other. Is this common?

I did that when I started but I learned that with all the tolerances in brass, primers, powder, bullets the "after" number could vary a good amount but mean nothing harmful OR could vary little and be unsafe.

[Ranch Dog]

The weight of the case does not matter in the least; volume does. Unless you are sorting by volume, it doesn't matter.

I will take it further. Weight matters only when sorted by headstamp. The assumption is that with a given headstamp, the brass alloy's specific gravity is constant, so weight can be an indicator of volume. There is no way to guess at the brass alloy's specific gravity across a mix of headstamps, so weight means nothing.

[Ohio3Wheels]

Depends

6.5mmTCU and 7mmTCU always.
Near max loads that I've worked up I stick with the headstamp that I worked them up in.
With compressed Black Powder cartridge loads I stay with the same brand in a given batch of loads, but have been known to load another batch in a different brand since I could never prove much difference.

Everything else it's pretty much load what I've got and that's particularly true with 9mm and mid-range 357.

Make smoke,

[RBHarter]

9 mm as a test case , not punny on purpose ....
I always separated by HS but after having read about a zillion posts on several forums I caved and loaded 50 rounds out of the 9mm bucket of otherwise homeless , lots of less than 100 cases and oddball HS . My load was worked in WIN cases and shot to the same place and repeatability with the various WCC , W-W etc Winchester and Olin corp HS . When placed into RP I had a huge number of stove pipes and failures to pick up the next round . S&B shot low and double taps shot low and missed high , primers displayed belly buttons around the firing pin dimple that may have been flow . IMI was in remarkable , FC , Speer , and Blazer in a further test resulted in a consistency likened to limp wristing with most shots running as planned 1-3 failures to pick up per magazine and enough stove pipes to make me cranky .

Under it does when it does I had a 308 that was a total garbage disposal . If it would chamber it would shoot a 2.5" or less group within 4" of point of hold at 100 yd , hot , cold , wet ,dry , 400' or 8000' .
I have an 06' that a change in case volume that amounts to the volume of 1 pellet of #8 lead shot and that one goes in a new group over there 12" . OAL doesn't matter in that one as long as it's all the same nominal OAL for a 150 BTSP it has .300+ jump a 230 gr cast seats out 3.99 OAL to touch .

You'll have better ammo and fewer bugs to swat if you start with matching HS .

[mikld]

I have one reason not mentioned above for sorting by headstamp; Boredom. I have way more time to spend in my shop than I have for shooting and often have too many loads to test and a good supply of proven handloads. So, for something to do I'll often sort. I inspect every case I reload so it isn't a big deal. I do keep some separate though. I have some 44 Magnums loaded hot that I keep separate with just one headstamp. My 308 and my 7.62x51 are separated by headstamp, but my 45 ACP, 9mm and revolver rounds more likely than not are mixed...

[sonic306090]

But When I separate the cases by Head Stamp, What do I do differently to each brand of headstamp?
I'm loading them all the same? 5.0 Gr CFE-PP / 124 Gr HP / OAL = 1.075

Is the reason for sorting headstamps just when shooting to avoid Gun Failures?