9mm dies over-sizing

[Twdmar]

I have a dillon carbide 9mm sizer die that sizes the brass down far more than I want and after seating the bullet, my reloads have a wasp waist or hour glass shape.
9mm case mouth external diameter should be 0.381" and this die squeezes them down to .370". Does anyone know of a die that doesn't squeeze it so much? I don't mind using lube either so non carbide is not out of the question.

 

[vegas]

Dillon 9mm dies are kind of known for that coke bottle shape. I use a Lee sizing die and don't have this issue. Only downside is the body isn't quite long enough to put the die nut on on the top and I had to tighten it from the bottom. Doesn't seem to be an issue on my 650.

 

[Twdmar]

That's what I figured, thank you

 

[Uncle Ed]

The more you load and resize your cases the harder the brass becomes and it will spring back more. This is where the reduced body diameter helps with bullet grip.

Many competitive pistol shooters use the Lee under size dies that reduces the case diameter .002 to .003 more than a standard die.

Below a wasp-waisted 9mm cartridge showing its increased bullet grip. The taper crimp is used for case mouth streamlining and has nothing to do with increasing bullet grip.

 

[Twdmar]

The more you load and resize your cases the harder the brass becomes and it will spring back more. This is where the reduced body diameter helps with bullet grip.

Many competitive pistol shooters use the Lee under size dies that reduces the case diameter .002 to .003 more than a standard die.

Below a wasp-waisted 9mm cartridge showing its increased bullet grip. The taper crimp is used for case mouth streamlining and has nothing to do with increasing bullet grip.

I understand that but I want something that works the brass a little less than the .010 of the dillon die.

 

[DocDoc]

When I get back home, I will have to measure some cases, but I do not remember my RCBS carbide set doing that.

 

[Twicepop]

If you're using jacketed bullets, this won't hurt anything. Your loaded ammo will be assured of proper feed (no bulged cases) and you'll also get a good grip on the bullet. If you're using a powder that has a tendency to burn dirty, the increased bullet pull will make the powder burn cleaner.

 

[243winxb]

9mm case mouth external diameter should be 0.381"

.381" is SAAMI loaded round diameter. If your sized empty brass was this diameter, there would be no bullet hold/neck tension, after seating a bullet.

My new RCBS 9mm Luger size die has a full tapered tungsten carbide insert. This should show less hour glass shape.

this die squeezes them down to .370".

Very close to normal, before the case is expanded. Remember, the die must work with many different brands of brass, with different case wall thickness.

 

[Uncle Ed]

I understand that but I want something that works the brass a little less than the .010 of the dillon die.

Your Dillon 9mm carbide dies has a long tapered carbide insert. if you think the die is over resizing your cases then raise the die to reduce the amount the diameter is reduced. Then check the cartridge for proper fit in "your" chamber.

If that does not work then just buy a standard Lee sizing die that does not reduce the diameter as much.

And if you go to the Brian Enose forum https://forums.brianenos.com/forum/72-9mm38-caliber/ you will see many competitive shooters use Dillon and undersize dies.

 

[243winxb]

What bullet is being used? The 147 gr bullets will have the shank deeper into the case. This may add to seeing the

wasp waist or hour glass shape.

 

[Timberyote]

It's nothing to worry about. I load 9mm, 40S&W on a 1050 and get the same thing, and they work just great.

My question to you is "do they chamber and fire OK?"