Topic: Checking for case stretching

[Spiff]

Just as an FYI, I have an RCBS CaseMaster that I normally just use to check case neck and bullet runout. A couple of weeks ago I was reading the instructions (gee, what a concept) and learned that a probe like part was an attachment that, in conjunction with the dial indicator, allows you to check the inside of cases for stretching that can lead to case separation.

I started checking .223 cases and so far out of about 800, I've found about 25 that had stretching to one extent or another. Probably 5 or so would definitely have separated the next time they were fired and one was so bad that I was able to break it in two with my fingers. Another was actually cracked yet you could not tell it until you knew a flaw was there.

It is time consuming, but I now have a lot of cases that I will reload at least one more time that otherwise would have been tossed. I don't have a pressing need for .223 ammo so I've just been doing a few a night. Also it's one of those reloading activities that you can watch movies while doing to help pass the time.

I know that some of you will be thinking that if there is any doubt toss the cases. But the tool does a good job and I feel certain that the cases I'm flagging as good, are indeed safely reloadable. Beats the shit out of just arbitrarily tossing several thousand cases.

[Spiff]

Just for a recap:

I finished with about 2k cases of .223. I found about 15 or so that were separating to the point of being paper thin and another 100 or so that had some stretching.

All in all, I feel pretty good about the technique. BTW, case thickness has a slight taper to it on the inside, thick near the head, and thinner near the neck (roughly .040 to .050 difference). When you check the cases you move the case through the dial indicator and probe and watch for the dial indicator to swing around in a nice smooth arc.

The cases on the verge of separating are easy to find, and you could probably find them with a hooked paper clip, however the tool makes it very easy. Basically, when you find a case that is on the verge of separating the dial indicator swings around and when it reaches the flaw it drops into it and makes a quick .010 swing. You can also feel it with the probe, so there's no missing the real bad ones.

The others that are stretched excessively are found by watching the dial indicator sweep around, stop moving (while your still pulling the case through), and then start again. The instructions call this normal stretching but I took the cases out anyway.

[Jeff]

Cool.  So, the real bad ones I should be able to feel by hand?  That should make checking for them pretty fast.

[Spiff]

Cool.  So, the real bad ones I should be able to feel by hand?  That should make checking for them pretty fast.

Yeah, the ones really on the verge of separating can be found with just a paper clip, there's no mistaking it when you find them.