Case Prep Question???

[ducks-and-bucks]

I have 50 cases of .243 winchester brass I bought new. They have 4 and 5 firings on each piece. I just got into neck turning and was turning these cases and after about 15 pieces I noticed a consistent high side of the neck on one side of the case every piece I was doing... ( does that make since) About half the neck was getting cut down, and the other side was not being touched by the cutter bit. I measured the neck thicknesses best I could with my calipers (I do not have a micro caliper yet). The thin sides were .13 the thick sides were .15

I started wondering if this brass if just short lived where its running now or if I may have a problem with my dies squeezing the neck to one side... (which I don't think there is a problem with the dies)

Is the winchester brass really that crappy? I can tell a huge difference between preping the winchester brass and lapua brass... to the point I could be blind folded and prep on them and tell the difference...

 

[bigedp51]

Look at the photo below and count the steps to make a .223 case.

Now ask yourself why online stores like Natchez, Widener's, etc sell brand new unprimed Lake City brass?

Or to put it another way, how bad does a military cartridge case need to be before its rejected and sold as scrap brass and then resold to us. And then the unsuspecting public asks in AR15 forums why their rifle shoots such big groups.

Winchester lost the contract to make ammunition at Lake City Army Ammunition Plant to ATK and ended up selling its brass manufacturing plant.

As long as production and stock dividends out weighs quality control people will keep buying Lapua brass made in Finland.

 

[Immike]

Adjust your turning tool until you just get a full cut or very close to it.

 

[GSPV]

Do you have a tight neck chamber? If not, you aren't helping yourself neck turning that brass.

Now, it's dang hard to measure case necks with calipers. That's why people use tubing thickness micrometers. With that said, is the cut or uncut places the thin places?

Assuming that they are, you just aren't cleaning up those necks yet. If the cut side is thin....

Another thought: what mandrel are you using to expand the necks before turning?

 

[bigedp51]

ducks-and-bucks

Your asking us to guess how your necks ended up with variations in neck thickness.

If you had the proper gauge to measure case necks you would be able to check them before and after shooting and reloading and answer your own question.

97% of all errors are human errors and only 3% are mechanical failures.

Tools for Measuring Case Necks
Consistent Necks Enhance Accuracy
http://www.accurateshooter.com/technical-articles/case-neck-mics/

All the information in the world is written in books, and all you have to do is read......................
And learn how to use the search function on AccurateShooter.com main page.

Do you have a tight neck chamber? If not, you aren't helping yourself neck turning that brass.

What he is saying is if you don't have a custom rifle barrel turning necks is a total waste of time. Its like parking a VW Beetle in a blimp hangar and bending your side view mirrors in so they don't hit the open hangar doors on the way in.

 

[K22]

Why are you turning necks on a 243 Winchester?

 

[pikespeakgoat]

Is there a certain dimension you're after? IMO I'd get a micrometer capable of accurately measuring the neck thickness to .0001" to confirm before and after dimensions before doing any neck turning. The mic will confirm your dimensions pre and post turning, but will aid you in your process as well, what's the final thickness needed, how much more do you need to remove...... unless you're just trying to take a clean up pass with no regard to specific thickness. In that case, just do as lmmike says.

 

[Cody Richardson]

I wouldn't say it's not helping, in a factory chamber it's not gonna do a ton but if your trying to take the 243 to longer rangers it will help in vertical spread. But for the most part if its not a tight chamber it's not doing a ton

 

[Immike]

It doesn't matter what it measures as much as they are all the same. What you are after is a equal release of the bullet from each case.

 

[STS]

A micrometer is on the way... The brass was being cut on the thicker side wall. I stopped all progress until the micrometer comes in. By the way it looks to me, I can even see a difference in the thickness of the neck on each side of the cases. It leads me to believe that the case as a whole, one side is thicker than the other. Which is a manufacturing defect. I may be trying to find some lapua brass asap.

Lapua brass has thick and thin spots also. Maybe not as much as another manufacturer, but they will vary in thickness. It's not a manufacturing defect as much as it is a unavoidable part of the deep drawing process. Bullet jackets suffer the same illness to some extent.

 

[Lapua40X]

What he is saying is if you don't have a custom rifle barrel turning necks is a total waste of time. Its like parking a VW Beetle in a blimp hangar and bending your side view mirrors in so they don't hit the open hangar doors on the way in.

LMAO... ;D I'm going to keep that one on file.

 

[GSPV]

And if you don't have dies with neck bushings, you are taking off neck tension as you take off brass.

IMHO, if you have a SAAMI chamber on that 243, there are lots of more productive ways to spend your time and money than turning necks.

I'd start with a custom barrel.

 

[kelbro]

You can buy and cull through a LOT of Winchester or Remington 243 brass for what a box of Lapua 243 costs...