.356 in 9mm

[MA5177]

Ok I already ran 100 of these through my glock with out a single problem, but I don't like the way they look.

I have 2k of 38 super 125 JHP that I want use up but it seems to bulge the case even though it's just slightly larger. Am I doing something wrong or is this normal? Using a Dillon 550. Here is a pic.

[rmatt]

wasp or coke bottle is totally normal in 9mm

[Cheep]

Don't over think this. Shoot them and enjoy.

[J-cat]

Pistol sizing dies are designed to size the thinnest case. This jeans they oversize the thickest case. Then you throw in a .001" oversized bullet into the mix and you get the coke bottle effect.

The reason you don't see this in factory ammo is because their brass is made on their dies.

[pacrat]

Dude, don't listen to them. They will blow up your shiny pistol.

But since you are close, I will still come and pick them up for free.

To Ah, ....You Know, save your shiny pistol from blowing up.

[NoHeavyHitter]

It's because 9mm bullets are .352 diameter.

[jericho89]

It's because 9mm bullets are .352 diameter.

Bullet diameter
9.01 mm (0.355 in)

[MA5177]

Thanks guys.. I will just shoot and not worry about it. I did some more reading over on brian enos and I guess it's mainly because 9mm is a tapered case and when you full length size them it straightens it out.

[J-cat]

No it doesn't.

[pacrat]

Thanks guys.. I will just shoot and not worry about it.

Does this mean that I won't be picking up several thousand free bullets?

Well Poop.

BTW........J-cat is correct. 9mm Para is a "straight tapered" wall case. That is .011" smaller in dia at the mouth than it is at the base. Different than a "straight walled" case like revolver cartridges. Many confuse the "straight" part to mean they are the same.

JM2c

[stilly]

So if the sizing ring is on the BOTTOM, then how does it know when to get bigger or smaller?


I saw another brand of dies somewhere that said they had a larger sizing ring or TWO sizing rings to make the 9mm more tapered and nice likee.

[pacrat]

So if the sizing ring is on the BOTTOM, then how does it know when to get bigger or smaller?


I saw another brand of dies somewhere that said they had a larger sizing ring or TWO sizing rings to make the 9mm more tapered and nice likee.

Good question stilly. One I didn't have an off the cuff answer to. So had to go upstairs and do some measuring to answer.

Can't speak for all die makers. My Lee 9mm carbide sizer. Unlike my other straight walled pistol dies. Does not have just a sizing ring at the bottom. [Never paid attention before] It has a "tapered Carbide sleeve" internally.

Sleeve extends to a depth of .550". Add the depth of a standard shell holder of .125". Makes .675". Leaving only .079" unsized at the open neck of the .754" case. That would be handled by the expander and bullet seating depth.

[ar15barrels]

It's because 9mm bullets are .352 diameter.

LOL at fail.

[ar15barrels]

I did some more reading over on brian enos and I guess it's mainly because 9mm is a tapered case and when you full length size them it straightens it out.

Most carbide dies will size the case LIKE a straight case, even though a proper 9mm case is a tapered case.
Old fashioned steel dies will size cases tapered, but you would need to lube the cases.

[J-cat]

False.

Carbide dies size size the 9mm using a tapered carbide insert. This insert is dramatically different from a carbide insert for a straight walled case. A 9mm carbide insert induces a tapered profile in a fired 9mm case. The body is larger in diameter at the case head and smaller at the case mouth. The degree of taper varies between die manufacturers.

If you ran a 9mm case through a .380 die you would end up with what you describe, but that is not the case with 9mm dies.