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Posted: 10/2/2010 9:00:05 PM EDT
I've been checking my cases after resizing using a case gauge, but always seem to have a few that just defy wanting to properly go into the gauge.  Every case that does it has just the bottom of the case sitting to far out of the gauge. I've run them through the die multiple times but can't seem to fix the issue.
Any suggestions? |
| I would start by checking the rim of the case. Some rims get roughed up enough by the extractor that they can have a bur that prevents them from going all the way into the case gauge. Take your finger and run it over the rim feeling for anything. A small piece of fine sand paper will rub it off, if that's your problem. |
If it's just burrs on the rims, swage them off. If case inserts backwards like in the pic, it will be GTG when inserted normally. eta, in my pic, that's a Dillon gauge. Lyman gauges are smaller at the rim, and some properly sized cases that have large but within spec rims won't gauge. |
| Checking the cases that had issues in the gauge, there were no burrs, but it seems that they all have a rub mark about 2/8ths of an inch above the bottom of the case. However, checking the cases against the light while looking at their sides shows no visible bulging. |
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Quoted:
Checking the cases that had issues in the gauge, there were no burrs, but it seems that they all have a rub mark about 2/8ths of an inch above the bottom of the case. However, checking the cases against the light while looking at their sides shows no visible bulging. The "rub mark" may be an indication that the cases are not being fully sized below that point. If the whole batch aren't all the same headstamp, I'll bet that the ones that don't gauge right ARE pretty much the same headstamp. Being a brass hound, I've found that some guns' chambers aren't as in-spec as others, and some brands are harder to size properly than others. I am not terribly concerned when I dump as much as 10% of range brass in the recycle bucket for various reasons, and "I can't get it sized properly" is a big one for me. The other issue, whether your Lyman gauge is telling you the cases aren't good because it won't accept a large but in-spec head/rim, is also something you can test with the "insert the case backward" technique. Burs and dings on the rim aren't always visible, but if it fits butt-first into the gauge that's an indication that burrs on the rim aren't a problem AND that the rim and head are within the Lyman gauge's tolerance. |
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Some brass resists being resized. If you are sure the rims aren't the issue, turn the die down another 1/10 to 1/8 turn and resize the stubborn cases.
Make sure they are being resized enough before doing all of them. Adjust the die accordingly. I have to run some brass in batches unless I don't care about oversizing some cases. I find IMI/TZZ brass resizes more in my dies than Winchester. I will have some oddball brass that resizes less than the Winchester using the same setting. I'm using Mo DeFina's case gages which are similar to RCBS's but better. The actually have a chamber cut into the gage instead of just indicating from the datum. |
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Quoted:
Yes I have a Lyman case gauge. Is that an issue? I've also tightened down my resizer to where it touches, then some. Just as the instructions say. I'll check the cases for burrs. Yes, the Lyman case gauge seem's tighter at the head than most other gauges. |
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