380 Load Problem

O

Overkill777

New member
I just got a Lee Die Set for 380 and loaded up some a quantity of 100 using magtech 95 grain bullets. I put a very mild flare on the cases. Upon seating I thought it felt like it took very little force. Upon inspection I realized there's very little case neck tension. So little that I can fairly easily push the bullet deeper into the case with my fingers. A crimp didn't seem to help. I realize this could cause a dangerous situation with over pressurization and quarantined these rounds immediately.

I'm not sure what is wrong, did I get a bad set of dies?

Edit: I forgot to say, this was on random once fired range brass that I have been accumulating. Brand of brass did not seem to matter.
 
Depending on the press it will spring not allowing full sizing of the case. Make sure the die goes down to the case holder. Also case wall thickness at the mouth varies with brand of case.
 
If you properly full-length sized the cases, you shouldn't have this problem.
Also, you should always do a push test on every seated bullet before your crimp. Crimp on a case that head-spaces on the case mouth is ONLY to remove the case mouth flare and has almost nothing to do with holding the bullet.
1) disassemble every case where the bullet can be pushed in. Inspect the bullets for crimp damage and bullet OD and compare to "virgin" bullets. Bullets pulled from a round should look and be the same size as they were when they went in the case.
2) size a case and try to place a bullet in it. If the bullet won't go in, sizing is OK. You can also measure the case ID and bullet OD to be sure that there is at least a 0.004" difference.
3) expand and flare a case. If the bullet can be pushed into the case, the expander may be too large. The expanded case ID (not the case mouth flare) should be 0.001-0.002" smaller than bullet OD.
4) seat a bullet and do a push test. If OK, go on. If it fails, go back and check your expander again as something is wrong.
5) crimp. Can you now push the bullet in the case? IF so, you are WAY over crimping and damaging the bullet. All you want is the case mouth flare to be reduced to the point where the case just drops in the barrel with a "plunk" sound.
 
Assuming your sizing die is within spec and your bullets are the proper diameter, I would have a look at the expander die. I have decreased the diameter on a few of these for more case tension on the bullet, I have two expander plugs for certain cartridges one is smaller than other for greater neck tension.
 
I know this may sound stupid, but are they really 380 brass?

There are various different 9 mm's out there, Markoff, Browning, Luger and others. What may look like one type could be another. Often when re-loading 9mm Luger I will find a 380 case (9mm Browning) or two mixed in with my brass. The cases are such that you really do not need to flare the mouths to seat the bullet. That could be a cause as well.

Since you can push the bullet in with your finger, I would tear them down and re-size then again without the case mouth being flared.

Good luck and stay safe.
Jim

9mm Luger is a slightly tapered case, 9mm Browning (380 Auto) is a straight walled case. Also make sure your die set is marked 380 Auto!!.
 
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