Confusing problem with sizing 9mm

[pistolpete10]

I use RCBS dies for 9 MM in my 550 and have not had any problems with chambering. I did add the Lee taper crimp die with the sizing ring in it because I do see a bulge on some of the loaded rounds. 

[noylj]

I run my 9x19 and 9x21 cases through the Lee 9mm MAK FCD as a bulge buster.

First, get a Lee or Hornady sizing die--they go down the case much further than other brands, particularly Dillon. This is the only reason I can imagine an undersized sizing die could be of any use with case bulges not being removed during sizing.

Next, you should learn to do a "Plunk" test so you KNOW where the problem is.

Plunk Testing:

The solution to chambering problems is to determine the cause:

Take the barrel out of the gun. Drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth a few times.

Remove and inspect the round:

1) Scratches in the ink on bullet--COL is too long

2) Scratches in the ink on edge of the case mouth--insufficient crimp

3) Scratches in the ink just below the case mouth--too much crimp, you're crushing the case

4) Scratches in the ink on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit

5) Scratches in the ink on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

[Yondering]

31 minutes ago, noylj said:

I run my 9x19 and 9x21 cases through the Lee 9mm MAK FCD as a bulge buster.

First, get a Lee or Hornady sizing die--they go down the case much further than other brands, particularly Dillon. This is the only reason I can imagine an undersized sizing die could be of any use with case bulges not being removed during sizing.

Next, you should learn to do a "Plunk" test so you KNOW where the problem is.

Plunk Testing:

The solution to chambering problems is to determine the cause:

Take the barrel out of the gun. Drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth a few times.

Remove and inspect the round:

1) Scratches in the ink on bullet--COL is too long

2) Scratches in the ink on edge of the case mouth--insufficient crimp

3) Scratches in the ink just below the case mouth--too much crimp, you're crushing the case

4) Scratches in the ink on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit

5) Scratches in the ink on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

 

This is a really good post, and worth reading twice for anyone having issues with this stuff. 

Edited July 15, 2019 by Yondering

[Chewy]

Yes, I've seen this post before.   I've marked my cases and they are all diagnosed "Poor sizing".   I'm waiting for my EGW u sizing die then I will try to size the cases again.

 

Thanks for everyone's help so far!

[Chewy]

Update:  

 

I've since gotten both the EGW undersizing die and the Redding sizing die.  

 

In testing both:  Out of the group of 30-35 cases that failed prior, they worked well.   Only about 3-5 cases now failed the case gauge, and of those they just barely failed with ~1mm from being flush.  Not bad.  

 

Thanks again for everyone's help!

 

[dtuns]

2 hours ago, Chewy said:

Update:  

 

I've since gotten both the EGW undersizing die and the Redding sizing die.  

 

In testing both:  Out of the group of 30-35 cases that failed prior, they worked well.   Only about 3-5 cases now failed the case gauge, and of those they just barely failed with ~1mm from being flush.  Not bad.  

 

Thanks again for everyone's help!

 

Sometimes cases that fail gauge pass plunk test in barrel. 

[Yondering]

49 minutes ago, dtuns said:

Sometimes cases that fail gauge pass plunk test in barrel. 

 

Yes exactly, and the barrel is the important test. The gauge means very little in comparison; it's place to start (for some) but making your ammo fit the case gauge should not be the ultimate goal, especially if you're loading for one specific barrel. 

[Sarge]

6 hours ago, Yondering said:

 

Yes exactly, and the barrel is the important test. The gauge means very little in comparison; it's place to start (for some) but making your ammo fit the case gauge should not be the ultimate goal, especially if you're loading for one specific barrel. 

I took the time to learn what fits my gun after failing gauge. There is no way I’m dropping 1000 rounds in my barrel. That’s why Hundos were created. LOL

  

[Chewy]

1 minute ago, Sarge said:

I took the time to learn what fits my gun after failing gauge. There is no way I’m dropping 1000 rounds in my barrel. That’s why Hundos were created. LOL

  

 

Yes.  I love my Hundo....hahah

[Yondering]

1 hour ago, Sarge said:

I took the time to learn what fits my gun after failing gauge. There is no way I’m dropping 1000 rounds in my barrel. That’s why Hundos were created. LOL

  

I only gauge the match ammo, practice ammo doesn't need it. (Unless someone has a really hard time with good die setup, lol.) 

 

If you had a case gauge that matched your barrel that would be ideal, but I'm not going to waste time gauging a bunch of ammo with a gauge that's tighter than I want my ammo to be. (Especially for coated lead bullets, which is 99% of what I shoot.)

Edited July 18, 2019 by Yondering

[GlockCanMan]

Chewy,

Where are you getting your brass from?  Is it just range brass that you are picking up from the field? 

[zzt]

On 7/17/2019 at 11:32 AM, Chewy said:

they just barely failed with ~1mm from being flush.  Not bad.  

 

Some pistols have very sharp extractors and cut the rim of the case.  I've found that if I take a file to the burr on the rim, the round will drop in completely.

 

My Shockbottle case gauge is a tad tighter than my chambers.  That is exactly how you want it to be.  If it drops into and out of the Shockbottle it WILL chamber in my pistols.  I use them in 40 and 9mm, and they work well with coated bullets.

Edited July 29, 2019 by zzt

[hceuterpe]

Don't want this to happen? Get a Redding sizing die. It sizes further down the case and has a true taper to the carbide insert, vs cheating like a Dillon which basically turns a 9mm case into a straight Wall case (but therefore also cannot size as far down).

The only downside is it is less forgiving to short stroking on say like during priming on a 650 which also acts to insert the case to resize.

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