9mm crimp

skhunter

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I am about to start reloading 9mm. Are you supposed to crimp the case like you would for a 44mag or are you just taking the bell out? I am a little confused because of the round headspacing on the mouth.
 
skhunter, if you have any sort of modern dies at all, they should have a taper crimp built into the seating die - and they should specify so on the packaging or on the die. mine state "taper crimp" and they're a set of dillon's.
 
Taper crimping is the only crimp for a rimless case. Mind you, if your load isn't too hot, just taking out the bell will do. At least for cast bullets.
 
Just remove the belling. The 9MM round like the .45acp relies on case friction to hold the bullet in place. The 9MM headspaces off the case mouth and you don't want to roll crimp this cartridge. I have found Unique at 4.7 gr under lead RN or Trucated boolits to be a very good load. Works well in my nines with no leading. What gun are you using?

Win 231 is another good powder for the 9MM IMHO.

STay Safe
 
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+ 1 on what LookOut said. The most of modern seating dies should have a crimp in it if set properly. However, if you are using a tight competition barrel, which at times could be picky on rounds that is being cycled in its feed ramp, then I suggest you buy a Crimp die (I use a Lee factory crimp die - it does not only crimp the lip of the brass, it also resizes the full lenght of the ammo at the same time). These should take care of your 9mm crimping. But if you are using an out of the box production 9mm handgun the crimp on the seating die should suffice.
 
Boomer said:
According to the Lyman manual a 9mm's case head is .394" and the case body is .391"....according to my caliper and UMC factory ammo - both the head and body are .385". I think we can call that rimless.

Honestly I've never bothered to verify or check...but I've been lead to believe it was semi rimmed (like the 38 Super)

It would appear not to be the case (pun intended)
 
In a reloading video with Brian Enos, he suggests running a case through the sizing die and then moving it over the the crimp die without belling it. You then adjust the crimp die to match the profile of the resized case.
 
I am using Dillon dies so the crimp die is a seperate die.It does not say but I am assuming it is a taper crimp. I was mainly asking if the crimp was more for removing the bell or for actually holding the bullet in place as in the .44. I am using a CZ-75. Will too much or too little crimp cause problems? If the rounds feed OK does that mean they have a proper crimp? I have not loaded for a semi-auto before, am I making this more complex than it really is? If I just follow the instruction with the dies will I be alright? I am going to use HS-6 powder.
 
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skhunter

I posted this earlier and I will post it one more time. All you have to do with a 9MM is remove the belling, little else. The 9MM bullet is held in by friction from the case unlike your .44 Mag or my .45 Colt which require a firm roll crimp. Using your Dillon crimping die just run the loaded case up to the point where you fell the case nudge the die at the top of the stroke and you are there. All the Lee Factory Crimp die does is resize the case down in size. I have loaded thousands of rounds of 9MM using cast, FMJ and plated bullets with nary a problem BUT you must remove the belling or you may experience feeding problems. I have the CZ 85 and it will feed your rounds like like soup in a soup kitchen.

Merry Christmas

Bob
 
Suputin said:
There is no real need to crimp 9mm. I use uncrimped ammo in both pistols and subgun with no problem.

Crimping is just that much more work and is uneccessary


I dont crimp 9mm either, the [LEE] seating die removes the flare and the stuff shoots just fine.
 
The 9mm case is a tapered case - there really shouldn't be a "bell". Taper crimping is usually done by the seating die to restore the taper and tighten the case mouth. I find, for me, crimping with a taper crimp die after seating, gives me a more consistent cartridge. Never roll crimp a cartridge that headspaces from the mouth. Revolver cartridges typically are roll crimped a) because they're headspaced from the rim and b) the loaded cylinder is more directly affected by recoil shock than a magazine, resulting in bullet creep if the crimp isn't tight enough. A roll gives it a bit of bite.
From my experience Win WSF powder burns better in 9mm than 231.
 
Skip the bell referred to is that which is applied prior to seating a bullet to allow for ease of entry of the bullet into the case. It must be removed by taper crimping the round. I know you know this but our enquirer is new to loading this particular round.

Stay Safe
 
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