Dillon 9mm Sizing Die Help

jtravisbayne · January 12, 2009, 07:13 PM

Need a little help. I'm getting back into reloading after a 15 year layoff. Just got my new Dillon 550B all set up. I sized a few cases and noticed that the area closest to the case head, maybe the first 1/8" past the head, "looked" larger in diameter than the rest of the sized case. I sized a few more with the same result, but thought maybe it was a reflection or something. Today, my new cast bullets arrived and I figured I'd try to get the depth on my seating die set and seated a bullet. For kicks, I went ahead and crimped it. After crimping, it looks like the sizing die is definitely not right as the crimped bullet is thicker than the middle of the case. It's almost like whole round has a Milkbone appearance in that the case head and the bullet end are thicker than the middle of the case. I'm still trying to dig up my calipers to get the exact measurements, but I was wondering if anyone had encountered this, or know if I might be doing something wrong. I'm going to contact Dillon to see if I might have the wrong sizing die. It's stamped 9mm, but it looks several thousandths undersized to me.

FireCop203 · January 12, 2009, 08:52 PM

The same thing happens to me as well with the 9mm Dillon sizing die. I changed to a Hornady sizing die and it didn't squeeze it down as much.

You might also check the diameter of the bullet you are loading and make sure it's the right size. I've found that different manufacturers don't have as much quality control as others.

If I remember correctly you can contact Dillon and send the die back to them and they can bore it out to a larger size diameter, but I could be wrong about this.

wwmkwood · January 13, 2009, 06:51 AM

9mm is a tapered case, you may have your sizing die set too deep. The best wat to set it is with a case gage, adjust the die down until the case just fits in the gage.

Alleykat · January 13, 2009, 10:02 AM

Lee sizing dies size more of the case than do Dillon sizing dies. I use no Dillon dies on my 650.

jtravisbayne · January 14, 2009, 08:12 PM

I adjusted the depth and the round still looked like I was staring in a carnival mirror. I had a set of RCBS dies for my old Rockchucker and screwed down the sizing die. Ran a couple through and Presto! looked fine. Measurements are within .003" on each end of the case. I'm going to the shooter's supply this weekend. I think I'll see if I can pick up a Lee 9mm sizing die and go with it.

Oldfalguy · February 23, 2009, 11:48 PM

Same thing for me. Bought the Dillon 650 about 5-6 years ago and just last week decided to try it out and darn if it didn't bulge the 9mm above the case head- tried it both lubed and dry, die set down tot he sheel plate and then up a bit. Ugh.
I guess Dillon dies are not as good as thier presses or what??

D. Manley · February 24, 2009, 12:01 AM

It's not an illusion and it's by design. Dillon sizes cases (particularly, 9MM) a bit more in the upper half of the case to ensure good case tension (think, setback prevention) on the bullet. Commonly called the "Coke Bottle Effect", which IMO, is a good thing. Do a little "Googling" and you'll find out more than you ever wanted to know about it. They're fine, load 'em & shoot 'em...

January 12, 2009, 07:13 PM	#1
jtravisbayne Member Join Date: December 27, 2008 Location: Simpsonville, SC Posts: 48	Dillon 9mm Sizing Die Help Need a little help. I'm getting back into reloading after a 15 year layoff. Just got my new Dillon 550B all set up. I sized a few cases and noticed that the area closest to the case head, maybe the first 1/8" past the head, "looked" larger in diameter than the rest of the sized case. I sized a few more with the same result, but thought maybe it was a reflection or something. Today, my new cast bullets arrived and I figured I'd try to get the depth on my seating die set and seated a bullet. For kicks, I went ahead and crimped it. After crimping, it looks like the sizing die is definitely not right as the crimped bullet is thicker than the middle of the case. It's almost like whole round has a Milkbone appearance in that the case head and the bullet end are thicker than the middle of the case. I'm still trying to dig up my calipers to get the exact measurements, but I was wondering if anyone had encountered this, or know if I might be doing something wrong. I'm going to contact Dillon to see if I might have the wrong sizing die. It's stamped 9mm, but it looks several thousandths undersized to me.

January 14, 2009, 08:12 PM	#5
jtravisbayne Member Join Date: December 27, 2008 Location: Simpsonville, SC Posts: 48	Conclusion I adjusted the depth and the round still looked like I was staring in a carnival mirror. I had a set of RCBS dies for my old Rockchucker and screwed down the sizing die. Ran a couple through and Presto! looked fine. Measurements are within .003" on each end of the case. I'm going to the shooter's supply this weekend. I think I'll see if I can pick up a Lee 9mm sizing die and go with it.

February 23, 2009, 11:48 PM	#6
Oldfalguy Senior Member Join Date: January 25, 2009 Location: Central Texas Posts: 126	Thought I was crazy and seeing things Same thing for me. Bought the Dillon 650 about 5-6 years ago and just last week decided to try it out and darn if it didn't bulge the 9mm above the case head- tried it both lubed and dry, die set down tot he sheel plate and then up a bit. Ugh. I guess Dillon dies are not as good as thier presses or what??

February 24, 2009, 12:01 AM	#7
D. Manley Senior Member Join Date: July 13, 2008 Posts: 299	It's not an illusion and it's by design. Dillon sizes cases (particularly, 9MM) a bit more in the upper half of the case to ensure good case tension (think, setback prevention) on the bullet. Commonly called the "Coke Bottle Effect", which IMO, is a good thing. Do a little "Googling" and you'll find out more than you ever wanted to know about it. They're fine, load 'em & shoot 'em... __________________ *"Old School" ain't all bad...*

January 12, 2009, 08:52 PM	#2
FireCop203 Member Join Date: October 8, 2008 Location: Oklahoma Posts: 22	The same thing happens to me as well with the 9mm Dillon sizing die. I changed to a Hornady sizing die and it didn't squeeze it down as much. You might also check the diameter of the bullet you are loading and make sure it's the right size. I've found that different manufacturers don't have as much quality control as others. If I remember correctly you can contact Dillon and send the die back to them and they can bore it out to a larger size diameter, but I could be wrong about this.

January 13, 2009, 06:51 AM	#3
wwmkwood Senior Member Join Date: December 24, 2008 Location: Kansas Posts: 110	9mm is a tapered case, you may have your sizing die set too deep. The best wat to set it is with a case gage, adjust the die down until the case just fits in the gage.

January 13, 2009, 10:02 AM	#4
Alleykat Junior member Join Date: July 26, 2007 Posts: 3,668	Lee sizing dies size more of the case than do Dillon sizing dies. I use no Dillon dies on my 650.