9mm Reloading Issue

[Zilberbak]

l have been given a 1000 used 9mm brass of various manufacture to reload with. However I am having an issue that is baffling me.

I am using a Lee Classic reloading press without the twizzle stick as l prefer to do batches of brass by process rather than cycle one straight in to a finished bullet.

The problem is that regardless of brass manufacturer about one case in 15/20 is over flared and the bullet head slips in in to the case. l can literally push the bullet head in or pull it out by hand. l then have to carefully resize the top of the case without punching out the primer and then seat the bullet head.

The majority of the bullet heads go in perfectly.

l have backed off the flare setting and have minimum crimp because of the nature of the 9mm case.

l am using the rounds for my Armalon and have shot about 100 without issue.

l am going to use the factory resizing die for the next batch to see if that helps.

Does anybody have any thoughts what the problem might be?

[Alpha1]

Have you checked the cases overall length. Have you trimmed them so they are all the same length.

[DavidRees]

l am going to use the factory resizing die for the next batch to see if that helps.

Does anybody have any thoughts what the problem might be?

If you did not resize the cases before flaring them with the expander die, then the neck tension when inserting bullets ready to be seated is likely to be quite variable. Definitely a good idea to full-length resize every case with pistol rounds, I find. Also helps when chambering the finished round.

David.

[Alpha1]

When you were given these 1000 cases as Davidrees said the first thing you should do is FULL LENTGH RE SIZE any cases you are going to re load.
The second thing you should of done is trim them ALL to the same length.

[mag41uk]

If you didnt use the sizing die in the first instance how did you decap?

Tony

[dromia]

Universal decapping die?

[25Pdr]

Zilberbak Said....

"The problem is that regardless of brass manufacturer about one case in 15/20 is over flared and the bullet head slips in in to the case. l can literally push the bullet head in or pull it out by hand. l then have to carefully resize the top of the case without punching out the primer and then seat the bullet head."


A loose 9mm bullet is not good.

I've done tests using a typical load of Bullseye and a 125Gr Round Bullet and was able to produce a compressed round with a OAL that using the following chart would interpolate to 70,000 PSI. That's double the working pressure of a 9mm. Just sayin

[smack]

A resized case should not allow a bullet to seat on it, so if you are flaring the top, it shouldn't go past the amount you have flared. Don't bother trimming pistol brass, 99% of people don't, it doesn't grow like rifle brass.
If any of the brass too long or junk (I doubt it), toss it. You got it for free. 9mm brass is cheap (or free if you know local BiB who shoot it), and plentiful. And even the worst 9mm brass lasts over 20 reloads.

[Sim G]

l am going to use the factory resizing die for the next batch to see if that helps.

Does anybody have any thoughts what the problem might be?

Well, I know where I'd start....

[Zilberbak]

I used the resizing/primer de-capping die first on all of the spent rounds as I thought this would be sufficient to resize the cases (obviously not).

I will use the factory resizing die and check the case lengths afterwards ditching duds as I go.

I have checked the integrity of all the bullet heads that I have already done and will check again before they go in to the magazine.

Thanks for the help. I will report back on the next batch.