Weirdness while reloading 9mm

[GetReal]

Every once in a while, maybe 1 out of every 20 or 30, the resizing die won't re-form the brasss corretly, such that once its loaded, the round won't fully chamber.

In fact, the outside of the case wall looks slightly bulged.

Far as I can tell, the OAL and "crimp" are correct. And the progresive press ram goes all the way up to the die face. (Dillon 550C)

Any ideas?

 

[rockchalk06]

Bulged below the bullet or on the side?

I would get this when loading plated bullets 1 out of 50 or so. Pulled them and the bullet was way out of wack.

Just a thought.

 

[afv338]

try backing off your crimp die just a tad should correct this

 

[Threadcutter308]

Every once in a while, maybe 1 out of every 20 or 30, the resizing die won't re-form the brasss corretly, such that once its loaded, the round won't fully chamber.

In fact, the outside of the case wall looks slightly bulged.

Far as I can tell, the OAL and "crimp" are correct. And the progresive press ram goes all the way up to the die face. (Dillon 550C)

Any ideas?

For giggles, take a bunch of the brass (before you run it through the press to reload it) and measure the OAL of each piece. I've found variances of as much as 0.015". If you set your crimp die for the shortest piece of brass (whether you knew it or not), it is entirely possible that the longer/longest pieces of brass would be bulged, along the lines of what afv338 is inferring above.

edit: I'm referring to once fired/range Goblin'd brass.

 

[1moaoff]

She likes bulges!

 

[salks]

Lee factory crimp die seems to straighten it out for me.

 

[Goes-Bang]

Is it re-sized range pickup brass, or new?

 

[GetReal]

Is it re-sized range pickup brass, or new?

1x brass.

 

[GetReal]

try backing off your crimp die just a tad should correct this

Logically that make sense but I can't see it being one out of every 20 or more... Unless that was just a long case

 

[Goes-Bang]

How hot is the load? What is the recipe, and power factor?

Idea:
Hot loads, cheap brass, +P ammo (or if you accidentally pick up brass from a USPSA major 9mm open gun) will sometimes bulge out the cases near the rim. This can only really be corrected by roll sizing (which isn't a cheap endeavor). Additionally if you're showing signs of that kind of pressure, I'd probably recommend pulling those cases from rotation.

Crimp induced over-pressure is also a good idea to check, as was mentioned.

A 9mm case gauge, might be a worthy investment. (It won't fix your problem, but it will at least allow you to quickly check your ammo for chambering issues.)

 

[Mike Casselton]

Change to a taper crimp and end the problem

 

[fyaman43]

Issues I recently had with rounds not fitting my case gauge were entirely due to under expanding and over crimping (while seating and crimping in one step). At least the problem went away when I expanded a touch more and backed off the crimp a bit...

 

[LtDan47]

You need to do a search for bulge busting 9mm, I have been there and done that too. It takes a Lee Bulge Busting kit and a 9mm Makarov die to get the cases straightened out. Reason why 9mm Mak die is that cartridge is not taper like a the 9mm Luger round.

 

[918v]

Some cases are more difficult to resize and they resist going into the die more than the rest. This causes the shell plate to deflect away from the die bottom. The case does not get sized correctly.

Separate your brass based on headstamp. Adjust your dies accordingly.

 

[Mainer]

Every once in a while, maybe 1 out of every 20 or 30, the resizing die won't re-form the brasss corretly, such that once its loaded, the round won't fully chamber.

In fact, the outside of the case wall looks slightly bulged.

Far as I can tell, the OAL and "crimp" are correct. And the progresive press ram goes all the way up to the die face. (Dillon 550C)

Any ideas?

Do you seat and crimp with same die? If so, variance in case length might be the cause. Crimping with Lee factory Crimp Die should solve the problem.

 

[GetReal]

Do you seat and crimp with same die? If so, variance in case length might be the cause. Crimping with Lee factory Crimp Die should solve the problem.

No seating at station 3 of the Dillon and crimping at station 4

 

[Mr Tibbs]

Over the years I’ve learned a few things about reloading 9mm brass. Military brass is thicker towards the case head.
Some commercial brass is made to Military specs, if your using different headstamps this could be a contributing factor
To your dilemma.

 

[GetReal]

Over the years I’ve learned a few things about reloading 9mm brass. Military brass is thicker towards the case head.
Some commercial brass is made to Military specs, if your using different headstamps this could be a contributing factor
To your dilemma.

Mixed headstamps, so yeah... that may be it ....