crimp die versus factory crimp die

[cbourbeau32]

I use Lee dies and have both the standard bullet seating crimp die and the factory crimp die. What is the difference? Thanks, Charlie

[daddywpb]

Factory Crimp Dies crimp by squeezing the case mouth evenly with collets. Most factory crimp dies have a crimp 'groove' in the seating die that pushes the mouth of the case in when it reaches the 'groove'. I use the lee crimp dies on all bottle neck cartridges. It easier to get a firm crimp without buckling the case neck. OAL is very important here too. It's impossible to get a consistent crimp without trimming cases. Standard crimping and inconsistent case length equals a lot of brass in the garbage.

[LaOtto222]

Here is my take on it. The standard crimp in your bullet seating die needs a crimp groove in the bullet. If there is not a crimping groove, the bullet seating die will not crimp the case mouth. At best, you get no crimp, at worst the case mouth will slide down the bullet and bulge out so much it will not chamber. When you have it adjusted correctly, the bullet is being pushed into the case; as it nears the OAL the ring in the die starts to turn in the mouth of the case into the crimp groove. If you do not have it adjusted correctly, it will bulge the case, just below the crimp or not give you a crimp at all. You have a fine line between not enough crimp or too much. If you do not have a crimping groove in the bullet or want an OAL that does not coordinate with the groove you can not use the crimp in the bullet seating die. You would use a Factory crimp die in those situations. I much prefer the Factory crimp dies. I can seat the bullet exactly where I want and not worry about the crimping groove or even if has a crimping groove. If I want to crimp in the groove, I set the bullet seater so that it seats the bullet to the cannelure and then run it into the FCD with out worrying if I am going to over crimp, under crimp or bulge the case.

[Catfish]

I crimp a very small portion of the ammo I load. I only crimp heavy recoiling round and handgun rounds. I personally do not like the Lee factory crimp die and do all of the crimping with the seating die. It is not necessary to have a cantilure to crimp in and even if I am crimping a bullet with a cantilure I rearly have the crimp in the cantilure. I have had to crimp in some bullets to the point I left a fairly deep ring in the bullet, but this never effected accuracy as far as I could tell. Lee says that case lenth has very little effect with their factory crimp die, but case neck thickness will have. Would you rather trim you cases to lenth your turn you case necks?

[daddywpb]

I have never had a problem and i don't turn case necks. The bullets I use in my .350 Rem Mag do have cannelures, but if they are crimped in them OAL is too short and they won't feed. I crimp them under the cannelure.

[LaOtto222]

Catfish - What bullet seating dies are you using? I have all RCBS and Lee dies for this with a couple of exceptions which are special seaters that do not have any crimping capabilities. With the dies that I have tried, I have found that I can not crimp a bullet out side a cannelure. They simply buckle the case mouth or crush down the shoulder in a bottle necked case. In a straight case, they bulge out just below the crimp to the point of not being able to chamber a round unless I make very careful adjustments. I do not shoot the same bullets all of the time, so every time I switch bullets, I have to readjust the dies. I MAY be able to trim all cases to the exact same length each time I reload and get by with a small crimp outside of a cannelure, with some of the dies I have. I have Lee and RCBS dies in 22 Hornet for instance. The Lee has no crimping capabilities at all and the RCBS will buckle the thin necks of the Hornet every time when I try to crimp. When I am reloading 44 Mag, I use them in conjunction with a cannelure. I have to be careful  about getting them adjusted so I get enough crimp with out bulging the case just below the crimp. I have found that with the FCD's I do not have to worry about case length being exactly the same or that I have to turn case necks. The ones for 357 and 44 Mag are carbide and turn in a crimp no matter where I want to put them, with out bulging or buckling the case. The bottle necked cases just squeeze the neck down, so again it does not matter what the case length is or how thick the case mouth is. I have not used these for a long time. I have just recently started to use them. I always tried to get by with no crimp and if i had to, I used a cannelure and adjusted the crimps very carefully. I really do not know what there is not to like about these crimp dies. The only  thing I could think of is that it takes an extra step in the reloading process and the expense of the extra die. I think this is easily off set by ease of adjustment and no case loss. Maybe there is some thing else I have not thought of. This is what makes us a great nation...choice - To each their own.

cbourbeau32 -  try it both ways and decide which is best for you.

[LaOtto222]

I have done some research on this subject on this site. Here is a link to someone that I think knows what he is talking about, at least with cast bullets.

http://www.gboreloaded.com/forums/index.php/topic,139623.0.html

What he says here makes perfect sense to me. I have a 357 crimp die that squeezes down the outside of the whole bullet/case. I will have to re-examine this die and how it pertains to my use (mostly jacketed bullets). The others I have squeeze the crimp in and will continue to use these when I feel  a crimp is needed. Catfish may have been referring to this when he said you have to turn necks, I am not sure. Turning a neck would thin the neck where the bullet goes so it does not "swedge" the bullet down to a smaller diameter. cbourbeau32 never said which cartridge he was talking about. If it is a die that squeezes down on the bullet, I say go for it. If it is the other type, then I would probably go with the crimp on the bullet seater into an existing cannelure, especially if using cast bullets, and be careful when setting the die so you do not run into problems like I explained above.

[gypsyman]

I prefer the Redding Profile crimp die. Starts out as a taper crimp die, but if you adjust it down far enough,you get a roll crimp. The only crimp die I could find that the bullets didn't ''walk out'' on me in my super mag calibers. Real pain in the butt when the 3rd. or 4th. bullet in a cylinder of .44's or .375sm  comes out far enough to stop the cylinder from turning, especially in the middle of a match. gypsyman