reloading 9mm and. 45 acp

What brand of dies are you using? Most seating dies crimp at the same time. Lee makes a factory crimp die. But their seating die that comes in the set can also crimp. It is up to the user to use whichever they want. I do taper crimp both of the calibers you asked about.

 

I picked some dies up at a local gun show and found a place to get "free" brass at an indoor range but my dies crimp.
I'd be interested to get some insight from the more knowledgeable.

 

Well that depends on the caliber. When you start out you size first. That will deprime at the same time. Then you expand the mouth of the case. That is so a bullet will sit in the mouth. Next you will install a new primer. Then you will charge with the proper amount of powder. Then you will seat a bullet. Most people will crimp at the same time. If you are doing a rimless cartridge like the 45 or the 9mm you will simply taper enough to remove the expansion that you put on the mouth of the case. This is a delicate step because if you dont crinmp enough the gun will not go into battery. (the slide doesnt go all the way forward) If you crimp too much you can cause the round to tumble in the air.

 

with taper crimping, after you size a case measure the outside diameter of the case mouth. then when you setup you crimp die only crimp enough to return the outside diameter to the measurement you took. crimping more than that will actually cause the bullet to loosen in the case and setback creating overpressure and possible kabooming your gun.

taper crimp is for removing the case mouth bell only. it is NOT for pressing the case mouth into the bullet.

the other type of crimp is roll crimping and those dies are used with cannelured bullets to roll the rim of the case slightly into the cannelured ring around cannelured bullets. never ever use a roll crimp on a cartridge like 45acp 40sw 9mm etc that spaces of the case mouth.

 

Taper crimp will work well, but the LEE factory Crimp die is an order of magnitude better.

 

Yes it will.

 

No.


Taper crimping is more than adequate on straight walled pistol cartridges.

You are securing the projectile in the case to prevent bullet setback during chambering.

 

The lee dies work just fine. I prefer them over other crimp dies. They are easy to adjust and easy to remove case mouth belling without over doing it. I use them to crimp 9mm and i use them to crimp 45-70 they work great on bottle neck cases as well.

You just have to know your minimum outside case mouth diameter, which you can obtain from a sized case

 

Yes. I have them for each caliber I reload.

I will keep this relevant to 9 mm & .45ACP. As far as the actual crimping itself goes, it does the same taper crimp as any other taper crimp die. Additionally, the Lee FCD essentially full length sizes the completed cartridge as well.
Some will argue that you shouldnever require this (the second full length sizing) process if you're doing everything correctly. I will only say, that with jacketed & plated, they may be right. Shoot a lot of cast and you will appreciate the additional insurance. Cast bullets brass will sometimes not wish to chamber due to the extra thousandth or two in bullet diameter. Naysayers will state that I am resizing the bullet unnecessarily and that it's bad to do that. Since I've used the Lee FCD, I've never have one of my rounds fail to chamber correctly. Previously I had some where the slide would not go the last 1/4" into battery.
Additionally, even without the full length sizing, many will argue that doing your crimping as a separate step is better as well. I would think that in principle at least, they might be right. In reality it's probably not that significant. The actual "crimp" required is little more than knocking down the bell you put into it earlier.

 

Canneluring is supposed to help resist setbacks (see my article on Setback). Factory canneluring is used on both of the cartridges that I studied, Hornady Critical Defense 9mm and Federal HydraShok 45ACP.

Is there a difference between the way the factory cannelures and the roll crimp you mentioned? I've started to look into reloading based on the latest ammo availability crisis, but know very little about it at this point. I'd like to be able to cannelure if it is possible and safe.

 

you dont cannelure a bullet during the loading process. a cennelure is created when the jacket is created. i dont use my lee dies to create a cannelure and i always crimp as a seperate step. if you try and create a cannelure as a secondary step you can cause jacket seperation on firing as the bullet exits the muzzle.

dont over crimp. a cartridge doesnt need a death grip to function in most semi-autos. cannelures are needed in belt fed machine guns too keep bullets from being extracted during loading. cannelures are also used in heavy recoiling rounds or tube fed firearms like lever guns.

 

OK, if I understand it right, the canneluring is the ring of ridges around the bullet. Some amount of crimping of the casing around the ring of ridges is what helps the cartridge resist setback. Excessive crimping can actually create problems with overpressure or with the bullet tumbling after leaving the barrel.

The Federal HydraShok 45ACP cartridges have a visible ring of ridges on the outside of the casing. The Hornady 9mm cartridges only show such a ring of ridges on the bullet itself right at the edge of the casing. I imagine that at the factory they have some fairly sophisticated equipment to make their respective canneluring approaches work. Another fine reason to use only factory ammo for SD purposes!

 

Yes, lee factory crimp will work with any standard press