How much crimp?

[NYDAN]

I have reloaded a few rounds of the 450 Marlin but I am not sure how much crimp to set the die for. The two factory loads have vastly different crimps. The 350 gr. FP has a severe crimp. The 325 gr. Flex Tip has a visible but not severe crimp.

I tried to follow the RCBS directions and couldn't even see a crimp. I lowered the die enough so that I could visibly see some crimp. The outside diameter of the crimp measures about 0.005" less than the case diameter just behind the crimp. Is that enough?

Dan

 

[SJB358]

Dan, I'll be that guy, I run the 10.00 Lee FACTORY CRIMP DIE. I turn it down about a 1/4 to 1/2 turn from where it contacts the case mouth and it does a perfect crimp every time and allow me to not have to monkey around with my seating die or crushing a valuable brass case.

 

[NYDAN]

SJB, Thank you. Fussing the combination seating and crimping die isn't my cup of tea. I will order a Lee FACTORY CRIMP DIE.

 

[SJB358]

Dan, I have one for all of my lever rifles. They work well, not a huge fan of Lee, but their FCD's are real good for their intended purpose.

You won't miss messing around with the seating die and you'll have to really work to crush a case!

 

[NYDAN]

Man, that Lee Factory Crimp Die is the "Cat's Meow"! Beautiful crimps. The accuracy of my reloads improved and the velocity variation disappeared. I shot groups of three with two different powder charges. The extreme velocity spread on one was 18 fps and the extreme spread on the other was only 8 fps. Last week the extreme spread was 35 fps with the RCBS seating/crimp die. Both groups today measured less than 1" at 50 yards.

SJB, thanks for putting me on to these crimping dies.

 

[Alderman]

From reading the Nosler manual I now realize the crimp serves two purposes.
1. It keeps the bullet from moving
2. With slow burning powders a good crimp is needed to insure good ignition.
With a faster powder apparently the crimp isn't ii needed for ignition so bullet stability is the goal therefore the crimp may not need to be as pronounced.

 

[HeathSexton]

Factory Crimp die fan here as well. I turn mine 1/2-3/4 on my 45/70 loads depending on what I'm shooting. The FCD is super easy to set and adjust and setup.

I have one in most chamberings just in case I decide to get all crimpy.

 

[SJB358]

Factory Crimp die fan here as well. I turn mine 1/2-3/4 on my 45/70 loads depending on what I'm shooting. The FCD is super easy to set and adjust and setup.

I have one in most chamberings just in case I decide to get all crimpy.

Ha! Never used them for bottleneck cartridges but I hear good things about them. Might have to give them a try. At least a comparison.

 

[ScreaminEagle]

Factory Crimp die fan here as well. I turn mine 1/2-3/4 on my 45/70 loads depending on what I'm shooting. The FCD is super easy to set and adjust and setup.

I have one in most chamberings just in case I decide to get all crimpy.

I might have to pick up a couple of these for pistol reloading. I get sick of trying the get the seater/crimp die set up just right. Usually end up crushing a couple pieces of brass in the process.

 

[SJB358]

Factory Crimp die fan here as well. I turn mine 1/2-3/4 on my 45/70 loads depending on what I'm shooting. The FCD is super easy to set and adjust and setup.

I have one in most chamberings just in case I decide to get all crimpy.

I might have to pick up a couple of these for pistol reloading. I get sick of trying the get the seater/crimp die set up just right. Usually end up crushing a couple pieces of brass in the process.

Those days are DONE with the Lee FCD. Plus it nicely resizes your brass when it comes from the crimp die so you can be sure they'll chamber correctly.

 

[iXanadu]

I use the Lee FCD on my 9mm rounds and love it. With regards to rifle rounds, I'm still researching. I've read that some feel that you "only" use the FCD "if" you are handloading a bullet with a cannelure. Others feel that the FCD "does not" crimp in a cannelure fashion and can (and should) be used on any rifle load.

I would love to find a thread with an experienced reloader, taking a non cannelure bullet and comparing with and without the FCD. Could that be you, SJB358?

 

[HeathSexton]

If I had to shoot pistol rounds that were crimped with the seater I would not own any pistols. The Lee FCD is all I use. 1/2 turn on all pistol rounds for me.


I knock all the carbide sizers out of my pistol dies. With cast I like to shoot .431" bullets from my .44's and that ring will size them down thus defeating the purpose of oversized cast bullets. A flat end punch, some bad words and a BFH is a product I call ring be gone.

I use the FCD in my 30/06 using the 130 TTSX since it has a small bearing surface. I put a small roll into the top grove and rock on.


From what I read as long as you are not crazy with the crimp they work great on bullets with no cannelure. If problems on ES/SD surface crimping can tighten that up.

 

[Oldtrader3]

Each turn of the threading stem (#10-40) on the seating die is .025 inches down and .025 inches in. I really don't want for my ammo to have a 3/4 turn deep crimp (.018 inches per side). A .005/.006 crimp is probably more than sufficient? This is 1/4 turn max! Just my .02 worth.

 

[Woodycreek]

Another FCD user! Started using them with the 10mm/40 S&W and 45-70. Have since used them with the 5.56 and 308 Win. The definitely help with smooth feeding in Semi auto pistols and I noticed my ES tighten up on the 308 and 45-70.

 

[Dwh7271]

I'm with the FCD guys.
9mm, 357 sig, 40, 10mm, 44 and 45. And now the 45-70.