Crimp setup

[Pocketsx]

I'm looking for some help on setting up my crimping die. Heres some background info first. I'm using a dillion 650 with dillion dies to load 9mm. 124g cam pro rn bullets. I have my oal set to 1.150.

This is the first time I'm setting up the crimping die and I am having a hard time figuring out what the bullet should look like after it's crimped. Both the books I have have the same general comments and maybe I'm being too picky but I can't tell if i'm putting too much crimp on and causing a buldge, or if it's not crimped enough.

The pic below has three different crimps. After crimping the one on the left, I thought I crimped it too much so I backed it off a 1/8 of a turn and the middle round was made. I still wasn't sure sure so I backed it off another 1/8 and made the one on the right.

All three fit into my 9mm check gauge without issue. Am I being too picky or is there a way to ensure I'm getting the proper crimp.

This is my first attempt at uploading a pic. Hope it works.
Thanks in advance

 

[ripitup911]

all 3 from the picture appear to me to be over crimped. i am not familiar with dillon dies but i assume your using a seating/crimping die. i would recommend getting a lee factory crimp die as it is a much better way to crimp straight wall cartridge. as for adjusting the die back the seater out and bottom the die out on a case then give it a 1/8 to 1/4 inch extra turn and that is usually enough depending on how much flare you are putting on your case you might need more. what your looking for is removing the flare and just slightly crimping against the bullet.

 

[ATOM]

I've always hated the term 'taper crimp'. I think it's misleading.

If you're reloading, say, .30-30 and the bullet has a cannelure, then you can crimp it to your heart's content and it's generally good because the round headspaces on the rim and because the crimp holds the bullet in place.

In a cartridge that headspaces on the forward edge of the case mouth (9mm Parabellum, .45 ACP, etc), crimping like you're doing is not only unnecessary, but will tend to allow the cartridge to go too far into the chamber, meaning that the firing pin may not be long enough to make full contact with the primers, meaning misfires. I've also heard it said that it can raise chamber pressures dramatically, but I've never seen any hard data on that.

Part of the reloading process is belling the case mouth just a bit to make inserting the bullet easier. What you're left with is a loaded round with the case mouth much too wide. So you need to compress it back to size - and that's a taper crimp.

My suggestion. SAAMI specs (http://www.saami.org/specifications_and_information/publications/download/205.pdf) say a loaded 9mm Parabellum should be 0.3800" at the mouth. (Good luck with that last 10,000th of an inch, OK?) So, assuming you're using a normal three-die set:

• On loading your first round, do everything normally until you're ready to seat the bullet. Put the belled and primed case with propellant into your press. Make sure the die is a bit high. The idea is to seat the bullet without changing the bell.
  
  
• Insert the bullet. Adjust the seating pin downward as you normally would until you get the right COAL. (The resulting loaded round will look odd because the bell will still be there.)
  
  
• Back off the seating pin, way high.
  
  
• Now gradually start screwing in the die and running the cartrdige through it with the press, taking it out and measuring the case mouth diameter each time with a good set of calipers or a micrometer. The visible bell will gradually go away.
  
  
• When you reach an outside case mouth diameter of 0.380", stop. Lock the die in place with the locking ring.
  
  
• Reinsert the loaded round, raise the ram to put the cartridge into the die. Screw down the seating pin until you feel it touch the bullet. Lock it in.

If you've done that right, you will be able to use those adjustments to load all the rest.

Don't worry about the case mouth not being folded inwards like the .30-30 we mentioned. Properly resizing the case (step on in the whole reloading process) will create quite enough tension to hold the bullet in place.

Good luck.