Where on the crimp groove?

[JWFilips]

on .38 spec /.357 mag cast Truncated Cone bullet (that has an integral crimp groove cast in at the top 3rd of the bullet) where exactly is the best place to seat the bullet relative the "case mouth edge" before crimping? centered on the deepest part of the groove, or slightly above, or slightly below center?
Thanks

[Wal']

Great question, I'm defering to the more knowledgeable here for this one.

Would like to know the best option myself. :cbpour:

[bobthenailer]

I personaly as a life long pencilnecky would seat the bullet so that when the case is crimped the bullet woud be almost at the top of the crimp grove of the bullet .

[44magLeo]

I seat the bullet to where the case comes just below the top edge of the groove, I then crimp in a second step.
Use a regular seating/crimp die. The Lee factory crimp works well on bottleneck cases but ain't worth a shoot on straight walled cases.
Leo

[JWFilips]

I seat the bullet to where the case comes just below the top edge of the groove, I then crimp in a second step.
Use a regular seating/crimp die. The Lee factory crimp works well on bottleneck cases but ain't worth a shoot on straight walled cases.
Leo

Well That's what I have been doing all along so I guess I'm on the right track ( just slightly below the top of the groove). I always seat the bullets first then pull the seater plug on the die and crimp separately.....however I recently loaded a bunch of Winchester cases ( which I have loaded 8x before) Did these the same as always but this time I had a problem with them fitting the cylinder in my S&W 19-3. Since nothing changed that I can tell ( same brass, same bullet same crimp amount) I got to thinking maybe I missed the "magic spot" on the crimp groove ( If there was such a thing)

[mdi]

I seat and crimp in two operations and run the bullet down so the case mouth is half a whisker below the uppermost inside edge of the groove (one full whisker = .013", so 1/2 that is roughly .0065"). I usuall use a pretty heavy roll crimp on all my magnum loads and this method has worked for mebbe 25+ years...

[Char-Gar]

A very heavy crimp to the bottom of the groove is seldom if ever necessary and most often would be harmful to accuracy. All it takes is to roll the case in far enough to you can't snag a fingernail on it as it passed over.

Therefore I seat the bullet so the case mouth is in the very top of the groove. To much groove showing could become a place for grit to accumulate. At least that is my theory.

[9.3X62AL]

I view crimping as a necessary evil, only to be engaged in when and if required.

1) To guard against boolits being pulled out under recoil, as in a revolver cylinder

2) To guard against boolits being shoved in, as in a tubular levergun magazine

Taper crimping is whole 'nother subject, and kind of a cuss word. I'm trying to avoid yellow and red cards from Admin for using such profanities, so I'll refrain from such activity.

[JWFilips]

When I started loading for my first "Roll Crimp" cartridge was this May when I got my S&W 19-3 I tried to come up with a sort of constant......... 1/2 wiisker ...now that is good! My first constant was a tip of my finger nail space between the upper edge and the bullet case....but that didn't last long since I didn't like to look of the cartridge with the small gap in the crimp grove. Eventually I graduated to "just shy of the top edge" as my not too precise measurement. I had read about the "fingernail test" so that is how I have been doing it for most of my loading since May. I just got a shock the other day when the cartridges refuse to seat in the cylinder I guess I may have over crimped them but I can't see how since I try to use a consistant 1/4 +1/8 turn of my crimp die once it bottoms on the edge of the case. Could the problem be that the Winchester brass is getting work hardened and the crimp is getting too bulgy?

On a separate note..... since this appeared in this thread ( I had asked about this in a previous thread and got no good answers: A "Very Heavy Crimp" well how do you describe that vs. a light or medium crimp? Is this something that can be measure or measured by the amount of tightnening of the crimp die or does it just have to be "felt"
( just figuring I may get an answer this time!:razz:)

& yes after loading a few thousand rounds of cast for a .40 S&W w/ taper crimp.... I can see those bad words billowing forth! I try for .001" greater then a tight hand tightened seat on the case edge ( just noticeable as a light line on a pulled cast .401" cast bullet)
Thanks For all your responses!

[rond]

The brass should be at the top of the crimp groove when using a roll crimp. After you set boolit depth back out seating stem and set crimp. Turn seating stem in until it touches boolit. You are now ready to seat and crimp your boolits in one step. The reason the crimp groove is so wide is so the brass can be crimped as the boolit is seated.