OK I know this is probably a stupid question, but......

[jonr]

In my last post asking what everyones favorite .45-70 deer load was I noticed a lot of folks were using the Lee factory crimp.

Why is this?

I am new to .45-70 loading and just ASSumed that it was best to roll crimp in the crimp groove.

Thanks!

 

Jonr

[jackfish]

The Lee Factory Crimp die places a crimp independent of case length, so cases do not have to be uniform in length.  A cannulure or crimp groove is not necessary to crimp with the LFCD.  The adjustment and crimping collets of the LFCD provide a measured, consistent and uniform crimp.

[TennesseeNuc]

jonr,
I prefer to use a roll crimp on cast bullets that have a crimping groove.  A roll crimp seems to fit that type of bullet the best without distorting the bullet.
However, jacketed bullets are another story.  A couple of years ago, on the old Marlin Talk, some recommended the LFCD to solve my problems crimping 405g Rem. bullets...the cannelure is in the wrong place to get the proper length for a Marlin.  I tried it and it worked just fine.  I have since used LFCDs on all of my rifle calibers.  If I remember right ,I think it was jackfish that offered what turned out to be very good advice.
Try one, It'll make your reloading much simpler. :grin:
(Thanks again jackfish)
Best,
TnNuc

[snowdog]

Hey there Tennessee,   I read your comments,  and it appears you
   have found the way to crimp the 405 Rems.    I have been having fits
   trying to crimp this rnd.   I too use the Lee Factory crimp die.  I have
   tried it on the 405's    I crimp them about an 1/8 inch above the
   crimp to get them to fit.... but If I apply  a little bit of pressure on
   the bullet it slips into the case,  what is the  "secret"  I really like
   the way the 405 shoot.  but just can't seem to crimp them correctly.

[TennesseeNuc]

snowdog,
On the Rem. 405's, just above the "shoulder"or hump, there is a section that is not tapered.  I seat the bullet so that the top edge of the case is just above that shoulder on the bullet.  When I crimp, the case is squeezed in on the non-tapered section of the bullet.  When I tried seating any deeper the crimping force would sqeeze the bullet into the case.  When I tried seating the bullet with the shoulder above the edge of the case, the overall length was too long.  It seems that there is just a small area that you can crimp properly on that bullet.  My overall length comes out to be about 2.483".
It took a little tinkering to get it set right, but it works OK now.  It seems that with this caliber and bullet combination, the Lee FC die is a must.  Keep playing with it... it will work, although it does get frustrating at times.
Best,
TnNuc

[dla]

what is the  "secret"  .

The secret is two-part
[list=1]

• You need neck tension - key if you are neck-sizing as you may need to size a little further down the case.
• You need to set the Lee FC die about 1/4 to 1/2 turn tighter than the factory suggested setup.
[/list:o]

If you can see mandrel pinch marks on the crimp, then you're probably tight enough. Test by dropping a cartridge on it's nose and then measuring OAL.