How does this happen?

[Mad Chemist]

I have 3 FCD dies. I do not use them. I suppose I might if my turret suddenly grows a new hole. But until that happens they'll stay in the box.

I have dummy rds that I used to use before I bought spare turrets. Now I just keep the calibers that I load most often on their own turrets. This saves quite a bit of time.

 

[jcwit]

Only crimp in a seperate operation and only use a taper crimp die for semiauto ammo.

WHY?

Been doing both the seating & crimping at the same time for years.

 

[bainter1212]

Just got done loading up 50 more rounds. I had to play with the seating die to get the crimp just right but no more crumpled cases. Learned tonight that it takes only a very small adjustment on that die to make the crimp too aggressive.

Thanks again folks.

 

[ArchAngelCD]

Just got done loading up 50 more rounds. I had to play with the seating die to get the crimp just right but no more crumpled cases. Learned tonight that it takes only a very small adjustment on that die to make the crimp too aggressive.

Thanks again folks.

In reality it's not the crimp itself (you mentioned .471"), it's the fact the crimp is being applied before the bullet is completely seated so that as you continue to seat the bullet it can no longer move into the case because of the crimp so it buckles the case.

It must be because you are using different brass because the procedure you explained on how you set the crimp/seating die is correct.

I'm glad you got the problem worked out...

 

[dbarnhart]

An over-enthusiastic crimp. You want to set the crimp portion of the die so that all it does is take out the expansion/belling of the case mouth that your expansion die put in.

What's happening is that the crimp is taking place before the bullet is fully seated. The seater pushes down in the bullet and creates that bulge in the base. (been there, done that.)