Topic: Sorting .223 Brass by Weight.

[monkeywrench]

I have a small supply of 1X LC brass, and am curious about loading up some accurate AR 15 loads. How much weight variation is acceptable for segregation. Are we talking each tenth of grain difference, grain, or gram difference here? Just curious. If it's tenth of grain then I will have alot of little categories.

[Spiff]

It would depend on what kind of accuracy your trying to achieve. Distances out to ~ 500 yards or so, probably would not be affected by a ~ .3 grain case weight variance. However distances out to 1000 yards might very well be. I would worry more about breathing and trigger control than a .3 case difference out to 500.

Also case weight variances might not mean an thing, as it depends on what is causing the difference. Is the case just heavier in the web area, where it might not affect displacement/capacity? Or is case wall thickness causing the difference? Case wall thickness could and probably would cause variances in capacity. Which would cause pressure differences.

What would be nice, would be to know if there is a one-to-one correlation between weigh and capacity if the difference is wall thickness. In other words, if the difference between two case weights is .3, does that translate directly into capacity if the walls are what are different? Or is it just a brass composition thing......

[NGO]

I don't have a case wall or neck gauge to measure, yet.

But the object is to remove as many variables as possible.

But given all the head-stamps are the same is the first thing, having them made at the same time is also important. separate by lot if you know that.

Next would be sizing them cartridge lenght, neck concentric inspection, then wight of cartridge.

Of course other variables like work neck hardening enter into the picture. If you flame anneal the brass you create more variables, use a lead dip to heat the brass evenly. Unless you cast your own brass then your don't have a big enough pot to get them exactly the same.


I think bullet weight is going to make a bigger difference at longer distances. So weight the bullets and match them.

Of course you would then need a device to spin the bullets and see if they are concentric around the point also.

By then of course you would be using a different bullet press, I'm at work but the dies that keep the bullet centered in the cartridge would be a must, to remove the variable of the bullet not being pressed into the cartridge perfectly straight every time.

Got to go conference call time.