Thread: What causes this

Are you getting consistent lengths having to back off and re try during seating?

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must be my super tough arms

I usually get it right first time unless i short stroke

the crumpeling did happen at the end of the stroke each time it did happen so it may well have been long cases, on those two particular that started the crumple then the neck tension took over, the neck tension was immense, it was hard work seating the bullets

The real quetion is how do you set up the Seating die?.Because a VLD is a boat tail (I assume) and the tolerances on the Lee dies is not that fine.
The way I set up a die is to put the case in the holder and then raise the case to max height .Then screw the die onto the case and back it off maybe half a turn,then with the projectile seater at max screw it in a bit at a time untill seating depth is set,with long projectiles sometimes you have to backup the die more than half a turn.
It is possible to size the neck too small ,but only measung the inside of the neck will tell you but I dought that is your problem.Another is check you have the right size projectile ,it's sometimes the most obvious things that we overlook.

Those cases are crumpled by 100 or 200 thou.

Yet, the bullet is seated right down into the neck - the ogive is at the mouth and its a long bullet.

So, I don't think its the bullet grabbing on a too tight / stcky neck. If it was, the bullet wouldn't have gone so far into the neck.

Something must be contacting the neck / shoulder itself. Its not just pressure on the bullet that's doing this.

The seating die was set far too short for those knackered rounds yet was apparently right for most of them ?

I've sometimes had the bullet seated about 100 thou too deep if the case isn't properly seated in the case holder. I have a co-ax press with sliding plates not standard case holders so its an easy mistake for me to make but perhaps it could happen if you got the base off line a bit in a standard setup ?

My 2c is to wind out the seating die itself from the press body using the lock ring. Then adjust the bullet seating depth by screwing in the adjusting screw for the seating stem into the die.

ps I've also had cases look like that after trying to size them by hammering into the wrong end of my lee loader !!

I think you are on the money there mate, what I think iv been doing is taking the case up till it contacts the die to get the correct seating depth, and stopping when it gets hard.
the problem occurs when i push past that point and the opening of the case must contact inside at the top of the die

problem cause seating die set down too far,
hiding the problem dirty case necks and not enough lube(so the contacting of the case is hidden inside the differculty

Ill reset my die next time before I use it again

yea mate its the correct projectile, thats for sure. or there would be some serious issues

Finally !

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Appears there is a shiny mark on the top of the case mouth.
I believe they are seat and crimp dies - fine on pistol but not on anything rifle.
It's crimping the mouth as its still tring to seat projectile.
Back the die right out and wind the seater in all the way.
Wind die down until you are close to seating depth then back the seater stem out a couple of turns and wind the die in a couple. Should be well clear of the taper in the top of the die.
You can you the taper crimp to crimp, but as a separate stage after seating.

Dies are RCBS two die set, I wasnt aware they crimped, but then again the instructions were for 3 different sets on the same page

I was thinking that the shiny rim was from forcing the case against the top of the die and it bieng squished against it?

They are the worst for it. The crimp is very steep and not gradual like Lee or dillon taper crimps.
Hornady will do it also
Back it out and good to go