Brass Wall Thickness

In another post I was having trouble getting acceptable accuracy out of my 160g H&G 242S design bullet. Limited testing showed that a tighter crimp helped accuracy a lot. I went from .469 to .465 and groups went from 3 3/4" to 9 shots into 1 3/4" at 50 yards. I had a flyer that brought the 10 shot group out to 2 3/4". So I am concentrating on the flyer. The brass was Misc. and I don't know what brand of brass it came from.
 So if crimp is so critical, then wall thickness of various brands of brass must make a difference, Has anyone measured wall thickness and have you found significant differences between different brands? I have always heard R-P walls are thinner than most.
 In the past I have paid little or no attention to sorting my brass by headstamp but with this lighter bullet I may need to start. I have used the 200 g. H&G bullet in the past and never gave it much thought.
 So does anyone have info on wall thickness by headstamp?

Greetings,

Brass wall thickness will vary by the lot with most manufacturers.

I have R-P and Western brass from the 60's and it measures, roughly, 0.008" wall thickness.

Recent R-P brass I have collected is closer to 0.010" wall thickness.

It does not hurt to sort by head stamp. Better yet, all the same lot number. In the "good old days" you could buy a Military shooter a nice dinner and in return get gifted with a bag of once fired brass.

If you are bored, buy a good quality tubing micrometer and measure each case. Here, you will also find that the brass may average 0.010" wall thickness; but, will not be uniform. i.e. 0.009" on one side 0.011" on the opposite side and 0.010" in between.

Your investigative effort to locate the reason of the flyer is well received.

Cheers,

Dave

And now to throw another variable in the mix. Flash hole size.

It may be a factor with other brands also, but Federal has several different sized flash holes. Both shoot very well when separated into their respective sizes. But your groups will open up when they're mixed.

That being said, when I tested wall thickness, with my .0001 tubing micrometer, the lots of Federal and IMI Match that I had were the most consistent. Maybe 1 out of 10 had .001 difference. The majority was .0000-.0007.

Now, to comment on Kermit's flyer. If you've got 9 of ten in 1 3/4" with 1 flyer opening it up with mixed brass. You're good to go with that load. It could have been a bad bullet base, weird piece of brass, shifting position on the bench the Ransom is clamped to (if applicable), momentary increased pull of gravity of the moon, earth shifting. You get where I'm going. You can drive yourself bonkers chasing that flyer. Even at 2 3/4" every shot fired would be within the 10 ring. And, there's nothing wrong with a 99 in slow fire.
Al

The fast way to sort brass for wall thickness is with one of these


https://www.amazon.com/gp/product/B01N34EOTV/ref=ppx_yo_dt_b_asin_image_o04_s00?ie=UTF8&psc=1

But in reality, it is a waste of time no matter how fast you do it.  Pistols  ARE NOT BENCHREST RIFLES.  There is little to no benefit to be gained by worrying about minutia in ammunition.   Your load shoots fine.  Segregate by headstamp and roughly by number of times fired, but otherwise just load a bazillion rounds of your load and go train.

Wobbley, +1.
If I may quote what I've heard before: "It ain't the arrow, it's the Indian".
Politically incorrect, but still relevant.