Overworked brass; identifying it, and safety of converting to other calibers

[wyrmzr]

I've got some .223 brass that has been reloaded a LOT. In some cases, a dozen times or more. Lately, I've even had some necks split, which I gather is from them becoming too thin over time.
Is there a good way to identify when brass is becoming overworked, and, if the .223 brass is overworked, is it reasonable to assume that I can trim it down to 300 AAC without running into further issues? Is there anything to look for before I try to trim down to the 300 AAC?

[CT-shooter777]

I been told, not sure if true, but if you take a paper clip bent with a small 90 degree hook on one end and run it along the inside of the case, there should be no unusual bumps or ridges.
The theory is that as brass is worked over and over it develops internal ridges due to flow of brass and reworking.
These cases should be discarded, never tried it, but it seems to make sense.
Others may be familiar with this.

[wyrmzr]

I did just find the trick with the paper clip; obviously, overworked case necks are easy to spot, as they're visibly thin. So, I at least need to make sure those cases aren't also thinned out along the base. Last thing I need is a headspace blowout on the 300.

[Le Loup Solitaire]

IIRC the trick with the paper clip was used with 30-06 to locate case separations or the beginning of them. The first clue of course was the shiny ring that appeared on the outside just forward of the head. This indicated stretching. Other indications of brass wearing out are loosening of the primer pockets and splitting of the necks which become too thin. Overworking the brass by crimping heavily or simply too many times will cause neck failure. Brass showing any of these signs should be tossed. LLS

[dtknowles]

Neck splits are from work hardening of the brass due to repeated sizing, annealing can prevent the splits. Insipient head separation is what the paper clip test is for. It is most likely caused by a headspace problem with the firearm or a size die that pushes the shoulder back too much. Converting .223 to 300 BO will probably require annealing and as long as the primer pockets are good and you don't have an insipient head separation problem you could convert .223's with neck splits if you anneal the brass first.

Tim

[EDG]

When your cases have had primers pressed in and out about 50 times the primer pockets get loose.
When that happens your cases are dead unless you can find some fatter primers.

If your brass is not lasting until the primer pockets are worn out then there is something in your reloading process that could be improved.

1. No hot loads that stretch the primer pockets - ever
2. Never ever size the case more than necessary. With a bolt gun used at the range you can size your cases with .000 to .001 longitudinal clearance. Autoloaders, pumps and lever guns may need .002 to .003 clearance. This minimal clearance will eliminate head separations due to excessive clearance. The Hornady and Wilson case gages used together will eliminate excessive clearance.
3. Anneal the necks say every 4 or 5 loads. Too much work? You will pay for it by reduced case life.

[Motor]

Any full length sized case will eventully have a head seperation. Though I'm not sure about cases sized with a RCBS "X" die. Have to learn about those yet.

Yes, the more you work it the sooner it will happen but if you full length size there is no stopping it. It's just simple ware due to reforming the shape over and over again.

.223s are kind of strange. They normally seperate about 1/4" up from where you would expect them too. Most seperate just above the thick web. Not the .223 its usually about 1/3 the way up the case.

If you want to learn about .300 BO I suggest you visit ar15.com's reloading forum.

Motor

[jonas302]

134614134615 Thats the bump you are looking for with the paperclip this one showed the bright line on the outside also it was a 30-06 casing I cut it short when I sectioned it

[leebuilder]

Plus one on the paper clip, i have a peened a pieice of copper wire with a cup like profile for extra sensitivity. Some brands of brass vary in the streach ring location. Sometimes you can tell just by looking at the brass. Always have a broken shell extractor in your shooting bag. 303 is notorious for seperating.
Most of the neck cracking i have encountered was from old brass or over worked brass.

[r1kk1]

I use new brass for case forming. I used to use military brass for some wildcats but I annealed them prior to necking up or down. Without annealing and necking up would result is quite a few split necks.

Take care

r1kk1

[Janoosh]

Dtknowles has nailed it. Split necks are from work hardened brass. Brass flows forward when fired. The base is what is thinned. The bright ring is the sign, and use wire to confirm.

[ioon44]

134614134615 Thats the bump you are looking for with the paperclip this one showed the bright line on the outside also it was a 30-06 casing I cut it short when I sectioned it

I also find that .223 Rem will show this bump just below the shoulder of the case, I shine a bore light through the primer hole to check for this bump.