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Kingzoyt

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I full length resized a 5.56 shell and checked it with a case gage and it drops in flush. I then seat the bullet and give it a light crimp. Rechecked with case gage and it stops as much as 3/16th from going flush. Not sure whats changing. Has anyone seen this before.
 
I'm guessing you buckled the shoulder
2 things to check

1) Did you chamfer the mouth? If you don't the bullet seating can "crush" the neck down into the shoulder

2)excessive crimp. Are you seating and crimping in the same station? If so back off the crimp completely, as in no crimp, seat a bullet (after chamfer) and check again

You can also take a sharpie to the case and see where it's rubbing. I'm guessing the shoulder is rubbed off and looks like a mushroom
 
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"Roger" to the above. Sounds exactly like you applied too much crimp and buckled the case right below the shoulder. Somewhat of a common thing to do. The round(s) will probably not chamber so disassemble the round(s) and resize the case(s).
 
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The thing is i have fired some 500 rounds with no feed issues. I am using a lee classic single stage so one die seats and another crimps. I can't see any mushrooming. When i place the bullet to seat it , it slides in straight, although i haven't used a chamfer on them.
 
In that case I really don't have much to reply to. You seem to be saying that bulging below the shoulder is not an issue and that some 500 rounds have functioned normally. So if only one round or so is the problem, hard to pin down the problem, but if those rounds will chamber, OK to fire them. Does the problem occur with a particular kind of brass or any kind? Chamfering or neck belling shouldn't make any difference unless lead bullets are being used, in which case belling is a requirement.
 
All it takes is a few thousandths. Make sure you debur the inside of the case mouths, sometimes the tension is too much and it will buckle the shoulder, which might not be visible. If the bullet was tough to seat or if you see copper shavings you probably pushed the shoulder some. Deburring should solve it.
 
Or maybe I have misunderstood the problem. I initially thought that just one round was the problem but the other 500 or so were fine. But maybe you are saying that all rounds fail the case gauge test but they all chamber properly. If that is the case, my guess is that after bullet seating, the expanded neck then is slightly oversize for the neck section of the case gauge, perhaps an indication that the neck section of the gauge is undersized. Have you tried a factory round through the gauge? But if the rounds all chamber and fire properly, I would just forget about the case gauge behavior. I load for over 90 rifles, which is not to say over 90 different calibers, and have never once used a case gauge. There have been other threads where use of a case gauge has suggested problems that may have been non-existent.
 
I full length resized a 5.56 shell and checked it with a case gage and it drops in flush. I then seat the bullet and give it a light crimp. Rechecked with case gage and it stops as much as 3/16th from going flush. Not sure whats changing. Has anyone seen this before.
Click to expand...

I would suggest using a micrometer, the case gage will measure a fired and full length sized case back to minimum length. another gage is the chamber gage. Chamber gages can be made from old barrels or from parts of the old barrels.

F. Guffey
 
Case gauges are good and bad. I agree with the above if it fits in the chamber of the gun you are going to use, who needs a case guage?? ( not me)

But, if it fits the case gauge before seating and crimping and not after something has gone awry. You don't have to seat/crimp in the same die to over crimp.

Try a round with NO crimp and see what happens. If it fits then you know you have applied too much crimp in those questionable rounds and need to back it off. It is also possible the brass is question is LONGER than the others, which can result in excessive crimp.

You said you applied a "light" crimp but it does not take much to deform brass, and the press generates way more force than people think, it doesn't take much to overdo it.

Black out the case with a sharpie too, that will show you where the hang up is.
 
Kingzoyt said:
I full length resized a 5.56 shell and checked it with a case gage and it drops in flush. I then seat the bullet and give it a light crimp.
Click to expand...

Kingzoyt said:
I am using a lee classic single stage so one die seats and another crimps
Click to expand...

More information please.

What die are you using to crimp?

Have you tried gauging these rounds before crimping?

What is your Case length?

What is your OAL?

What bullet are you using?

Do they fit(chamber) and extract in the rifle?
 
This is simple: Don't crimp

1. It is not needed. Normal neck tension is more than enough
2. It's another step adding unneeded* perturbation to the process.
 
Try a round in the case gauge after seating the bullet, but BEFORE crimping. This will tell you if the seating process is causing the problem. If so, as others suggested, try chamfering the inside of the neck and try again. If still a problem then your die is not properly adjusted. Take it out and readjust from scratch following provided directions.
 
Any time there is a "fit" issue measure! Use your micrometer and measure the loaded cartridge's OD. At the case head, mid-way, and the neck. Use your calipers to measure the OAL. If you know where the case is too big, then you will have a good chance of identifying when it gets too big. Without facts (measurements) it's all a WAG...
 
But at any rate, we would like to be informed of the bottom line solution if any. It seems there are only two alternatives, either an answer to the case gauge situation was found or things are just going to proceed satisfactorily as they were. Too often it seems the OPs do not follow up with a solution if there was one. Solutions to problems can be beneficial in later threads of a similar nature. It seems like the best suggestions here are to seat a bullet without crimping and then try the case gauge test and then try again after crimping the bullet. While possibly not leading to a definite answer, it could point to a possibility (over crimping), or just leave us back at square one again.
 
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