Roskoe

This was something I kinda got forced into back in the 60's. My first set of dies were hand dies for the .303 British. One of the older sages in my home town offered me an upgrade - an ancient Lyman press for free - only problem was that it had a little alignment problem. Only way to seat bullets reasonably straight was to do it in about four steps; rotating the case each time about 1/4 turn.

On the oversize shellholder, I generally use a .308 shellholder for the 6MM PPC, and a .220 Swift shellholder for seating rounds with the .308/30/06 case head. They fit loose enough so the round is going to find the center of the seater die without any interference from the shellholder - but still hang onto the case just enough so it isn't going to fall out of the shellholder. Roskoe

Pawildman

Like you and bc, I've been turning the casings during bullet seating for some time, but never thought about the oversize shellholder.....Thanks!!

HEAD0001

I have had good luck using the Sinclair mandrel to size the inside of the neck. I only shoot my rifles as a single shot, and I orient the brass in the chamber the same every time. I like my brass to "FREE FLOAT" in the shell holder while bumping down the neck, Then sizing the inside with the mandrel instead of the sizing die.

I do not have any precision reamed(or custom match)chambers on any of my rifles. And I doubt if any of my rifles have truly concentric and aligned chambers, and throats. I have found that if I allow the brass to "FREE FLOAT" in the shell holder, that it automatically aligns the bullet while I seat it. But I am pretty sure that you guys have better rifles, and can probably shoot better than I can. But this method has increased my accuracy. And basically that is my major concern.

If I ever get a true target rifle with a perfect match chamber I sure will try what you guys are talking about. Tom.

HighDesertWolf

I did a little experimenting the other night I decided to use my lee classic cast as the lab rat incase I messed anything up anyway I removed the clip ring in the shell holder seat on the ram and eased a rubber o-ring over it into the groover that the little metal clip originally sat now the shell holder moves freely. I originally stopped using my classic cast because of the excessive run out i was experiencing that I blamed on the two piece ram. anyway long story short I loaded up some 308 rounds and the run out is now within .002" to .004" before it varied as much as .014"

guys get rid of those shell holder clips and replace it with a rubber O-ring. No need for any other remedies. good luck

Roskoe

Head - are you using the tailstock of a lathe to neck the cases with the Sinclair setup?

haugenna

I am bringing this back from the archives because I had might have some problems with the way I am seating bullets.

Correct me please if I am screwing up....but when I seat my bullets I run the bullet up the die and hold the brass to the back of the shell holder with my finger. I run the brass up half way, spin it, and then run it up the rest of the way while holding the brass to the back of the shell holder. Could this be a potential problem? Is this a big NO NO?

HEAD0001

No. The Sinclair sizing mandrel is basically a die that has different caliber mandrel's. I use it to size the inside neck diameter(basically bringing it back to caliber). I use it instead of the sizing ball on a regular sizing die. That way the expander ball on the regular die does not affect the brass at all. I think the expander ball is the "ROOT OF ALL EVIL"-so I get rid of them. IMO there is no way the expander ball can stay perfectly centered in the case, and I also believe it has an affect on the shoulder when you are resizing the inside of the neck.

I also use the mandrel after I clean my brass, and I use sizing wax. I do not get any friction when I do this.

I definitely agree that runout is very important, but I am more concerned with chamber alignment. And since I shoot all my rifle's in single shot mode, I seat all my bullet's into the lands.

BC is right when you have to worry about bullet jump-but bullet jump does not concern me. I do have bulet jump in my lever actions, but I cast all my bullet's for my lever's, and quite honestly minute of deer accuracy is all I worry about in my lever's. Tom.

bigcountry

I used to do it this way. For over a decade, but last year found that there is slop in shell holders and actually best to pull out the spring holder out and let the shell holder float like one of the posters said. Awesome tip.

I go further and bounce the bullet in the seater and back out to let the brass center itself. Its made a world of difference.

jeepkid

BC, so its probably not good when I put the bullet in the case and run in all the way up without turning it at all? Could that be part of my problem with the Bergers?

bigcountry

Could be, could not be. Roll your finished cartridgeon a mirror or something and see if the bullet wobbles noticably. When seating, just bring the ram up to touch the seater plug and back off, and see your case moves out in the shell holder. If it does then thats slop inthe shell holder. Some shell holder/seater combos, do not move at all, and some like my 7mm08, moved out several mills.

Its made a world of difference in my runout.