Brass Flow, 223 Converted to 222

[AccelR8]

Just thought I'd share this.

The chamber length on my 222 Remington measures about 1.714 inch. I have some new WW Super brass that measures, out of the bag, an average length of about 1.680 inch. So there's a difference of about .034. Pretty good gap IMHO. Also, some of the bullets I've worked with, keeping a reasonable amount of the bullet shank in the cartridge neck severely limited how much I could adjust bullet jump during load development.

So I decided to convert some 223 brass over to 222, to enable me to wind up with longer cases of about 1.708” or so. Also just for something to do.

I found that R-P brass gave me what appeared to be the most consistent converted cases in terms of weight and H2O capacity, followed by LC. I converted some of each over from 223 to 222. Since I have a .246” neck in my chamber I turned all case necks to .010” thick., they all turned out in the range of .0099” to .0103.” Best I could do.

Here's a picture of a typical fired and resized R-P case. This one has been fired and resized 2 times, with an anneal between firings. It was trimmed to length after the first cycle. The lop-sided difference in length is about .014 inch. Also, the neck is now .0120” to .0125” thick.

Brass flow obviously. I don't see this with the LC cases,at least not to any significant degree.

I just thought it was interesting to see this amount of change. I guess the solution is don't use the R-P brass for this.

 

[Uncle Ed]

Do the new Winchester cases when fired stretch and thin in the base web area?

Any reason why you can't use fire forming methods that holds the case against the bolt face?

The brass flow with the formed Remington .223 cases is ugly and to me shows how uneven the case wall thickness is.

I use a RCBS case mastering gauge like below to measure case wall thickness and stretching in the base web area.

My guess is your Remington cases do not have a uniform case wall thickness. And causing uneven brass flow during sizing.

 

[AccelR8]

Do the new Winchester cases when fired stretch and thin in the base web area?

Any reason why you can't use fire forming methods that holds the case against the bolt face?

The brass flow with the formed Remington .223 cases is ugly and to me shows how uneven the case wall thickness is.

My guess is your Remington cases do not have a uniform case wall thickness. And causing uneven brass flow during sizing.

I haven't tried any of the Winchester cases yet. I will do that.

I will find a long bullet, seat it to jam (thereby holding the case head against the bolt face) and fire form, then keep a close eye on Win cases.

My assumption also is greatly varying case wall thickness. I should section some lengthwise and see what I find.

I thought I was pushing the shoulder back about .002" during fl resizing but maybe I need to revisit that. I had set my die, but strangely things seem to change all by themselves in my shop. Seriously.

 

[RegionRat]

The NECO concentricity gage has an internal anvil set up for checking the runout of case wall thickness down in the middle of the body wall.

A few decades ago, it was hard to find brass with the same quality we have now, and that body wall thickness is one of the major improvements with good/better modern brass.

I used to see huge wall thickness runouts in some lots of commercial brass back in the 70's and 80's to the point where we used to file an index mark in the rims if we were forced to use the stuff.

We kept track of the thickest/thinnest walls and always loaded them to the same index point since once the case was neck turned and fired the index mark made it easy to know where the clocking should be.

When those body wall thickness issues came to the necks and shoulder junctions, you could see the extreme ones would affect the blend in the neck turn at the neck to shoulder radius.

If we were going to wildcat or fireform, we had issues with the batches that had high body thickness runout, so we tried to buy bigger lots and sort/cull, or on occasion we got lucky with better brass. We are spoiled these days....

 

[jepp2]

Do the new Winchester cases when fired stretch and thin in the base web area?

His dimensions are chamber length, not case head to datum. Given that, why would you expect them to stretch an thin as if the shoulder was significantly short?

 

[Uncle Ed]

His dimensions are chamber length, not case head to datum. Given that, why would you expect them to stretch an thin as if the shoulder was significantly short?

Because the ejector and firing pin will push the case forward and leave .034 headgap clearance. Why else would the OP be making "LONGER" .223 cases into .222 brass.

Just thought I'd share this.

The chamber length on my 222 Remington measures about 1.714 inch. I have some new WW Super brass that measures, out of the bag, an average length of about 1.680 inch. So there's a difference of about .034. Pretty good gap IMHO. Also, some of the bullets I've worked with, keeping a reasonable amount of the bullet shank in the cartridge neck severely limited how much I could adjust bullet jump during load development.

The thinner upper section of the case will grip the chamber walls when fired and the rear of the case has to stretch to contact the bolt face.

 

[AccelR8]

My apologies, I should have been more clear. These are the dimensions I was talking about:

 

[AccelR8]

I'm not sure what my chamber length to the datum point is, or exactly what my cartridge base to datum point is ether. I have the Hornady type (mine is actually Stoney Point) comparator tool which as you know is only that, a comparator not any type of gauging tool.

 

[Uncle Ed]

My apologies I misread the OPs posting "BUT" his new cases are at the minimum of SAAMI manufacturing tolerances.

I would think the cases will be longer after firing and full length resizing.

 

[tsyarnall]

^^^